back to indexThe Science of Vision, Eye Health & Seeing Better | Huberman Lab Podcast #24
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Welcome to the Huberman Lab Podcast,
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where we discuss science and science-based tools
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for everyday life.
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I'm Andrew Huberman,
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and I'm a professor of neurobiology and ophthalmology
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at Stanford School of Medicine.
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This podcast is separate from my teaching
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and research roles at Stanford.
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It is, however, part of my desire and effort
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to bring zero cost to consumer information
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about science and science-related tools
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to the general public.
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In keeping with that theme,
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I'd like to thank the sponsors of today's podcast.
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Our first sponsor is Roka.
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Founded by two All-American swimmers from Stanford,
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Roka eyeglasses and sunglasses have really been designed
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with the utmost care and the utmost attention
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to the science of optics and the visual system.
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So one of the things I like so much
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about Roka eyeglasses and sunglasses
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is that they're extremely lightweight.
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If you get sweaty, so for instance,
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if you wear them while running or walking or hiking,
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they don't slip off.
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And with the sunglasses, when you're outdoors,
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if there's cloud cover or if there's shadows
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or if the day gets brighter or dimmer,
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you can still see your surroundings perfectly well.
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And that's because the designers at Roka
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really understand the way the visual system works,
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how it habituates, how it adapts.
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You don't need to understand the science behind all that,
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but they do, and as a consequence,
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the eyeglasses perform extremely well under all conditions,
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whether or not that's indoors or outdoors.
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So they put a ton of science and purpose into the design.
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They also happen to look really good.
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They have a really nice aesthetic.
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A lot of, as you know, performance active wear eyeglasses
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look rather ridiculous, but the Roka glasses,
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I think have a very nice aesthetic to them
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that you could wear anywhere.
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If you'd like to check out Roka glasses,
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you can go to Roka, that's R-O-K-A.com
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and enter the code Huberman at checkout,
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and you'll get 20% off your first order.
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That's Roka, R-O-K-A.com and enter the code Huberman
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at checkout for 20% off your order.
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Today's podcast is also brought to us by Inside Tracker.
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Inside Tracker is a personalized nutrition platform
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that analyzes data from your blood and DNA
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to help you better understand your body
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and reach your health goals.
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I'm a big believer in getting regular blood work done
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for the simple reason that many of the factors
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that impact our immediate and long-term health
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can only be analyzed from a blood test.
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And now with the advent of modern DNA tests,
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we can also get insight into our specific DNA makeup
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and how that influences our lifestyle choices
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and our health status.
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The problem with a lot of blood tests
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is that you get a lot of information back,
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but you don't always know what to do with that information.
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With Inside Tracker, they have a very easy to use,
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personalized dashboard platform
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that informs you what sorts of lifestyle, nutrition,
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exercise changes you might want to make
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according to the levels of particular metabolic factors,
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hormone factors, et cetera, in your blood and DNA.
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So it makes everything very simple,
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both in terms of where you're at health-wise
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and what you should or could do
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in order to improve your health,
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something I do believe most everybody would like to do.
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With Inside Tracker, it makes all that very easy.
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They also have something called the Inner Age Test.
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This is a test that shows you what your biological age
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and compares that, of course, to your chronological age.
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And of course, your biological age
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is really what you want to know
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because it's a predictor of how long
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you're going to live and the quality of your life.
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If you'd like to try Inside Tracker,
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you can visit insidetracker.com slash Huberman.
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And if you do that,
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you'll get 25% off any of Inside Tracker's plans.
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Just use the code Huberman at checkout.
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Today's episode is also brought to us by Helix Sleep.
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Helix Sleep makes mattresses and pillows
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that are ideally suited to your sleep needs.
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Everybody needs something different
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in terms of what to sleep on.
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Some people like a hard mattress,
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some people like a soft mattress,
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some people tend to run warm,
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some people tend to run cold.
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With Helix Sleep, you go to their website,
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you take a very brief two-minute quiz,
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and you answer some questions such as,
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do you tend to sleep on your stomach
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or your side or your back?
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Maybe you don't know,
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do you tend to run hot or cold, et cetera?
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At the end of that quiz, you match to a specific mattress.
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I took that quiz about six months ago
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and I matched to the dusk mattress.
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And I've been sleeping on a dusk mattress
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from Helix for the last six months.
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And I've been sleeping better than I ever have before.
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Basically, everyone's unique and Helix understands that.
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And that's built into the design of their mattresses
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and this two-minute quiz that you take to match you to one.
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If you'd like to try a Helix Sleep mattress,
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you can go to helixsleep.com slash Huberman,
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You won't get charged, you'll get your money back, et cetera.
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So that's helixsleep.com slash Huberman
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for up to $200 off and two free pillows.
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We are now beginning a new topic
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for the next four to five episodes
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of the Huberman Lab Podcast.
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Before we move into that,
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I want to just briefly touch on a couple of questions
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that I got from the last episode,
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which was related to the science of endurance training.
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I described the four kinds of endurance training.
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We posted protocols of the specific four kinds
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of endurance training at HubermanLab.com.
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Just go to that episode.
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You can see the download.
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It's a zero-cost PDF.
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I got a lot of questions
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about what's called concurrent training,
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which is how to program endurance training
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if you are also interested
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in strength and hypertrophy training,
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or how to incorporate strength and hypertrophy training,
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which was in the previous episode, with endurance training.
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This can all be made very simple.
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Ask yourself, what are you trying to emphasize?
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And then emphasize that for a 10 to 12-week cycle.
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So if you're mostly interested in endurance,
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I would say use a three to two ratio.
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Maybe get three endurance training workouts per week,
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maybe four, and two strength and hypertrophy workouts.
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If you're mainly focusing on strength and hypertrophy,
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get three or four workouts for strength and hypertrophy,
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and do two endurance workouts.
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Start with the minimum number of sets that's required
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to get the result that you want.
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So if you're not accustomed to doing endurance work,
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you would start with the minimum number
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that's listed on that protocol.
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So if it says three to five sets,
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you would start with three, maybe even just two,
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and then work your way up by adding sets each week.
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I do suggest that people get
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at least one complete rest day per week,
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although I know a lot of people don't like that.
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I benefit from that.
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I actually benefit from having two complete rest days
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I just continue to make progress that way,
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whether or not it's for strength and hypertrophy
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I am a big believer in rest days.
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Other people are not.
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And those could be active rest days, hiking,
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relaxing, et cetera.
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After a 10 to 12-week cycle,
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then I also suggest taking anywhere
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from five to seven days completely off.
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You can still enjoy life and do things.
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I know for you addicted exercisers
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that you're going to loathe to do that,
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but that's one way to stay injury-free,
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keep your joints and tissues healthy over time,
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and continue to make progress.
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If you don't want to do that week off, don't do it.
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None of this is holy.
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None of it is a strict prescriptive.
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Just ask yourself, what are you going to emphasize?
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And emphasize that in terms of the total volume
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of workouts that you do and work up incrementally
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and then move into another cycle.
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That's what I suggest.
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So go to hebermanlab.com.
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You can get the protocol there.
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We are now going to move into a new topic
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unrelated to physical performance,
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starting with this episode.
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And for the next four to five episodes,
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we are going to talk all about the senses.
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That's sight, eyesight, hearing, touch,
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And we are also going to talk about this critical sense
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that we call interoception,
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or our sense of our internal real estate.
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Now, the reason that we are talking about the senses
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is because if you understand
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how the senses are perceived,
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what they're about,
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what the underlying cells and connections are about,
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you will be in a terrific position
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to understand the month's topic that follows,
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which is all about mental health.
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Now, I want to emphasize that if you're somebody
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who doesn't have any trouble
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seeing, hearing, tasting, smelling,
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and has an excellent sense of interoception,
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I do believe that these episodes
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will still be very relevant to you
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because they have everything to do
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with how you move through the world,
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how you make sense of information,
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and how you organize your thoughts and your emotions.
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I also want to emphasize
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that we're going to cover a lot of practical tools.
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So today's episode is going to be all about vision
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and eyesight, a topic that's very near and dear to my heart
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because it's the one that I've been focusing on
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for well over 25 years of my career.
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But we're not just going to get into the mechanistic details
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about how light is converted into electrical potentials
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and things like that.
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We are going to talk about practical tools
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that you can and should use
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to help maintain the health of your visual system
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and your eyesight.
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Very often, young people will say, what should I do?
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You're always talking about neuroplasticity
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and how it tapers off over time,
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but I'm a young person, what should I do?
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You should absolutely train and support your eyesight.
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In fact, if you're a young person and you see perfectly
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or you feel as if you see the world perfectly,
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you are in the best position to bolster,
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to reinforce that visual system
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so that you don't lose your vision as you age.
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In addition, you can leverage your visual system
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for better mental and physical performance,
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and we're going to talk about that.
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If you're somebody who suffers
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from a clinical disorder of vision, you have trouble seeing,
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or if you need corrective lenses in order to see,
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this episode is definitely for you.
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And while, of course, I can't make clinical diagnoses,
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I can't have a one-to-one conversation
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with any of you in this format, nor am I a clinician,
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I'm a scientist, not a physician,
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I did consult with our chair of ophthalmology,
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Dr. Jeffrey Goldberg at Stanford University
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School of Medicine, as well as several other people
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to really vet the information and make sure
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that the protocols that I'm describing
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are consistent with the clinical literature.
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If you have a severe eye problem,
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you should be working with a really good ophthalmologist
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and or optometrist, but certainly an ophthalmologist
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who's a medical doctor.
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But I do believe that the information
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that we're going to discuss today
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is going to be relevant to everybody,
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and we'll set the stage for the month on mental health.
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And mental performance.
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So let's get started.
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When we hear the word vision,
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we most often think about eyesight or our ability
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to perceive shapes and objects and faces and colors.
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And indeed, vision involves eyesight,
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our ability to see shapes and objects
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and faces and colors and so forth.
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However, our eyes are responsible for much more than that,
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including our mood, our level of alertness,
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and all of that is included in what we call vision.
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So I just want to take about three, maybe four minutes
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and talk about how the visual system works,
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how it's built and how you are able
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to so-called see things around you.
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I also want to describe the ways in which your eyes
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and your visual system impact your mood
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and your level of alertness.
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And then we are going to get right into some protocols,
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some specific things that each and all of you
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should do if you want to enhance your vision
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and maintain your vision as you get older.
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And again, if you're a 15-year-old or a 12-year-old,
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this episode is especially for you
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because your nervous system is far more plastic
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It's much more amenable to change.
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So you can really build a very strong visual system.
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And in doing that, and if you adopt specific behaviors
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at any age of light viewing at particular times
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in particular ways, then you can build an emotional system
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that's also reinforced by your visual system.
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So let's talk about vision.
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Well, vision starts with the eyes.
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We have no what's called extra ocular light perception.
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While it feels good to have light on our skin,
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while it feels good to be outside in the sunlight
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for most people, the only way that light information
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can get to the cells of your body
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is through these two little goodies
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on the front of your face.
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And for those of you listening, I'm just pointing to my eyes
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as many of you have heard me say before
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on this and other podcasts, your eyes in particular,
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your neural retinas are part of your central nervous system.
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They are part of your brain.
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They're the only part of your brain
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that sits outside the cranial vault.
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In other words, you have two pieces of your brain
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that deliberately got squeezed out of the skull
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during development and placed in these things
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we call eye sockets.
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There's a genetic program for the specific purpose
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of making sure that three little layers of neurons,
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nerve cells got squeezed out
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and form what are called your neural retinas.
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Now the eyes have a lot of other goodies in them
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that are very important.
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And those are the goodies
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that we're going to focus on a lot today.
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There's a lens to focus light precisely to the retina.
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If you're somebody who requires eyeglasses or contacts,
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chances are you don't do that correctly.
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And so that's why you use other lenses
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like eyeglasses or contacts.
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There are also other pieces of the eye
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that are designed to keep the eye lubricated.
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You also have these things that we call eyelashes.
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Most people don't know this,
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but eyelashes are there to trigger the blink reflex
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if a piece of dust or something gets in front of your eye.
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It's a beautiful adaptation of nature.
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They aren't just aesthetically nice.
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Costello happens to have very long eyelashes.
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He gets compliments about this all the time.
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Maybe you have long eyelashes.
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I don't have particularly long eyelashes,
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but the eyelashes are there
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so that if a piece of dust or something
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starts to head towards the cornea,
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the eye blinks very, very fast.
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It's the fastest reflex you own is your eye blink reflex.
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We also have these things called eyelids.
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Now, eyelids might seem like the most boring topic of all,
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but they are incredibly fascinating.
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Today, we're going to talk about
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how you can actually use your visual system
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to increase your levels of alertness
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based on the neural circuits
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that link your brainstem with your eyelids.
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And no, we are not going to have a blinking contest
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because I would win and you would lose,
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and that wouldn't be fun for you.
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So let's talk about what the eyes do for vision.
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Basically, the entire job of the eyes
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is to collect light information
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and send it off to the rest of the brain
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in a form that the brain can understand.
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Remember, no light actually gets in
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past those neural retinas.
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It gets to the neural retina,
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and we have specific cells in the eye
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called photoreceptors.
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They come in two different types, rods and cones.
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Cones are mainly responsible for daytime vision,
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and the rods are mainly responsible for vision at night
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or under low light conditions, generally speaking.
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So basically what happens is if your eyelids are open,
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light comes into the eye, the lens focuses that light,
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light is also just called photons, light energy,
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onto the retina, these photoreceptors, the rods and cones,
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have chemical reactions inside them
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that involve things like vitamin A,
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and that chemical reaction converts the light
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Now, that might seem incredibly abstract,
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but the way to think about this is very similar to,
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for instance, you have touch receptors on your skin,
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and when you press on those touch receptors,
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they convert pressure, physical pressure,
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into electrical information, and those neurons send it up
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to your spinal cord and brain can register that somebody
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or you are touching the top of your hand, as I'm doing now.
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With the eyes and the retina,
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it's just that light gets converted
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into electrical information.
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Within the eye, within the retina,
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there are then a series of stages of processing,
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and that information eventually gets sent into the brain
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by a very specific class of neurons.
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I would like you to know the names of these neurons.
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They're called retinal ganglion cells,
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so the only thing you need to know
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about the neuroscience of the eye at this point
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are that they're rods and cones.
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The cones are involved in bright daytime vision,
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and rods are involved in more dusk or nighttime vision,
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and you've got these cells called retinal ganglion cells
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that send the information off to the rest of the brain.
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Now, here's what's incredible.
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I just want you to ponder this for a second.
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This still blows my mind.
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Everything you see around you,
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you're not actually seeing those objects directly.
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What you're doing is you're making a best guess
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about what's there based on the pattern of electricity
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that arrives in your brain.
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Now, that might just seem totally wild
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and hard to wrap your head around,
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but think about it this way,
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because this is the way it actually works.
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Let's take an example of a color like green or blue.
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You have cones in your eye that respond best
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to the wavelength of light
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that is reflected off, say, a green apple.
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So you don't actually see the green apple.
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What you see is the light bouncing off that green apple,
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and it goes into your eye,
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and you see it and perceive it as round and green,
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but not because you see anything green.
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No green light arrives in your brain.
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What happens is your brain actually compares
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the amount of green reflection coming off that apple
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to the amount of red and blue around it.
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Well, you might say, well,
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the green apple is sitting on a brown table
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or a white surface.
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Well, then it will appear very green
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because the amount of wavelength of light for green
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is very high, and the amount for red is very low,
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and so it looks very green, okay?
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So we don't actually see anything directly.
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What the brain is receiving is a series of signals,
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electrical signals, and it's comparing electrical signals
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in order to come up with what we call these perceptions,
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like I see something green, a green apple, or I see red.
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Let me give you a slightly different example.
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If you were to play a key on the piano,
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let's say you play, I'm not a musician,
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but I'm going to, so I'm,
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hopefully I won't get this too incorrectly,
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but let's say you have like E sharp,
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and maybe it's on ding, ding, ding, ding, ding.
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If the brain gets that signal, it doesn't actually know E.
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That's what, it doesn't recognize it
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until you were to play another key next to it,
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dun, dun, dun, dun, dun,
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and what it does is it does the math,
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it does the subtraction, and it compares those two.
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So when we see something green or we see something red
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or we see something blue,
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we're not actually seeing it directly.
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The brain is making a guess
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about how green or red or blue that thing is
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by comparing what's around it, okay?
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And if that seems hard to wrap your head around,
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don't worry because we will explain it
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in more depth going forward,
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but I really want people to understand this,
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that vision, eyesight is not looking at things directly
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and that information getting directly into your brain.
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Light information is transformed into electrical signals
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that your visual system exquisitely understands.
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Now, what does this mean?
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Why should you care about this?
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Well, if you have a dog like I do or a cat,
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they are not colorblind,
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but they lack the cones that respond to red,
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meaning long wavelength light.
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So what does that mean?
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That means that when they see green,
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it's different than the green you see,
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not because that apple isn't visible to them,
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but because they aren't able to compare it to red
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As a consequence, when they look at a green lawn,
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it looks more brownish or orange to them.
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When you wear a red shirt in front of your dog or cat,
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if you see a stop sign and they see a stop sign,
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they see orangish brown and you see red,
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presuming that you are a trichromat,
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meaning you have three color vision.
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So this is all to say that every animal
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sees the world differently depending on whether or not
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they have one or two or three of these different cones,
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the red, blue, or green cones.
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If you are a mantis shrimp of all things,
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you see hundreds of colors that human beings can't see.
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Many animals see into visual ranges
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that you and I can't see in.
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So for instance, a pit viper senses heat emissions.
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It literally sees the heat coming off of you
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or of an animal that they want to eat.
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If you are a ground squirrel, you can see ultraviolet light.
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This is going to sound kind of weird,
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but ground squirrels actually signal one another
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by standing up outside and shining sunlight
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off each other's stomachs to each other,
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signaling at a distance, just like, you know,
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you could signal somebody with a mirror
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in sunlight at distance.
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There are species of primates,
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this isn't very pleasant to think about,
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that urinate on their hands
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and then wipe it all over their stomach
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and then use that sunlight to reflect
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different signals to each other.
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I don't know what they're saying.
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We always assume it's something cute and nice,
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but maybe they're insulting each other.
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So this actually gets right down to the heart
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of these bigger questions like consciousness.
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How much of life is really accessible to us?
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And I could go on and on.
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You know, this used to be kind of an obsession of mine
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when I was coming up in the field of visual neuroscience
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to understand how different animals
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see the world compared to us.
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You know, I'll give one more example, a diving bird,
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you know, a bird that flies over the ocean.
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It has an incredible task.
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It has to both view the horizon
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and it has to view schools of fish.
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And then it has to make a trajectory down into the water
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and grab one of those fish to eat.
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And the water has what's called a refractory index.
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It actually shifts like a prism,
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the impression or the perception of where that fish is.
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If the bird sees the fish right below it,
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it has to know, it has to adjust its diving trajectory
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just right because it knows that that fish
link |
actually isn't where it sees it.
link |
It's probably a few inches ahead or to the side of that
link |
because of the way that water diverts the image.
link |
If you've ever dropped a coin to the bottom of a pool,
link |
if you go straight down looking at that location,
link |
if you were to look from the top of the pool
link |
and you dive straight down with your eyes closed,
link |
you will miss because the water refracts.
link |
It shifts the visual image.
link |
Well, diving birds have an arrangement
link |
of these retinal cells that communicate to the brain.
link |
That's both a streak to view the horizon
link |
because they need to know where they are
link |
relative to the horizon.
link |
And they have a pupil like we do on the bottom of their eye
link |
so that they can make very accurate dive
link |
and attacks on these schools of fish
link |
and catch fish and eat those fish.
link |
We just have pupils in the middle of our eyes.
link |
So there's a ton about the optics of the eye
link |
and the way that it communicates with the brain
link |
that allows us to see.
link |
We could spend hours talking about this,
link |
but what I'd like to embed in your mind
link |
is that what you experience in the outside world
link |
is bottlenecked, it's limited by which wavelengths,
link |
which colors, if you will, of light that you can see,
link |
that your brain is coming up with a best guess
link |
about what's there, it doesn't actually know what's there.
link |
And that your vision is distinctly different
link |
from say the vision of a dog
link |
or from the vision of somebody who's a dichromat,
link |
meaning they don't have a red cone.
link |
A lot of people in particular about one in 80 males
link |
lacks a red cone and therefore sees the world
link |
much the same way that Costello does,
link |
although he sees it from just much lower toward the ground.
link |
So that's what I'd like you to understand
link |
about the way the eye communicates with the brain.
link |
I would also like you to understand
link |
that the brain itself is making these guesses
link |
and that those guesses are largely right.
link |
How do I know that?
link |
Well, they're right because when you reach out
link |
to grab a glass, most of the time you grab the glass
link |
and you don't miss, right?
link |
Most of the time when you make judgments
link |
about the world around you
link |
based on your visual impression of them,
link |
it allows you to move functionally through the world.
link |
But let me give you some examples
link |
of where this guessing is happening right now.
link |
And it's so incredible that to this day,
link |
this still blows my mind.
link |
Cover one eye with one hand,
link |
if you're driving, maybe don't do this.
link |
If you're viewing the world around you,
link |
presumably you can see everything that's out there.
link |
I could do this with one eye or the other eye.
link |
You probably see better out of one or the other,
link |
and we'll talk about that.
link |
You have a giant blind spot
link |
in the middle of your visual field.
link |
It's called your blind spot.
link |
It is the spot in which the connections,
link |
the wires from all those retinal ganglion cells
link |
exit the back of the eye and head off toward the brain.
link |
In other words, you are blind
link |
for a huge spot of your central vision,
link |
the part of your vision that's highest acuity,
link |
highest detail, and yet you don't see that ever.
link |
You cover one eye and you see perfectly fine.
link |
And it's not just because your eye
link |
is moving around really quickly.
link |
Your brain is guessing what's in that spot,
link |
which is absolutely incredible.
link |
And so you don't see that blind spot.
link |
This is happening all the time.
link |
Now, when you have two eyes open,
link |
the way that your eyes are positioned in your head
link |
and the way they view the world
link |
is such that they fill in each other's blind spot.
link |
So it's pretty convenient.
link |
But if you cover one eye, that's impossible,
link |
and yet you still see the world as complete.
link |
So the brain is doing these incredible things.
link |
It's also creating depth, a sense of depth,
link |
even though what arrives from the retina
link |
is essentially a readout of a two-dimensional flat image
link |
so it can sense depth.
link |
How do you know depth?
link |
Well, this is very simple.
link |
Things that are closer to you tend to be larger
link |
than things that are far away.
link |
Things that are closer to you
link |
tend to look like they're moving faster.
link |
If you've ever been in a train and you look to your side,
link |
the rungs on a fence or the train tracks going by you
link |
look like they're going very fast.
link |
If you look off in the distance,
link |
they look like they're moving very slowly.
link |
And there are differences
link |
between what's close to you and what's further away.
link |
So a little house on the horizon,
link |
you don't look at and say,
link |
oh, that must be a tiny little house.
link |
You have some prior knowledge
link |
that things further away are smaller.
link |
So that's the main way that you do that.
link |
And you compare the location
link |
at which information about light lands on the two eyes.
link |
So your eyes are slightly offset from one another.
link |
So that, for instance, if I look at you,
link |
if you're standing right in front of me right now
link |
and I were to look at you,
link |
the image of your face,
link |
the light bouncing off your face, to be more precise,
link |
lands on one eye in a slightly different location
link |
than it does in the other eye.
link |
And then the brain does math.
link |
It basically does the equivalent of geometry
link |
and trigonometry and essentially figures out
link |
how far away you are from me,
link |
which is just incredible.
link |
So the brain does all this very, very fast.
link |
And the brain uses about 40 to 50%
link |
of its total real estate for vision.
link |
That's how important vision is.
link |
Now, for those of you that are blind
link |
or low vision or no vision,
link |
that real estate in the brain will be taken over
link |
by neurons that control a sense of touch
link |
and a sense of hearing.
link |
And you're indeed hearing and touch are much better,
link |
higher acuity and faster in blind people.
link |
But for most of you who I presume are sighted,
link |
this is how it works.
link |
So that's kind of vision from eye to brain in a nutshell.
link |
There are a bunch of different stations in the brain
link |
that do different things.
link |
Now I want to talk about the other aspect of vision,
link |
which is the stuff that you don't perceive,
link |
the subconscious stuff.
link |
And then we'll transition directly
link |
into how you can use light and eyesight
link |
to control this other stuff,
link |
because it's very important in that other stuff
link |
is mood, sleep, and appetite.
link |
And there are ways in which you can use
link |
the same protocols that I will describe
link |
in order to preserve and even enhance your vision,
link |
your ability to see things and consciously perceive them.
link |
So the protocols we will describe have a lot of carry over
link |
to both conscious eyesight
link |
and to these subconscious aspects of vision.
link |
And I just want you to understand a little bit more
link |
about the science of seeing, of eyesight and vision,
link |
and then all the protocols will make perfect sense.
link |
So as amazing as eyesight is,
link |
it actually did not evolve for us to see shapes and colors
link |
and motion and form.
link |
The most ancient cells in our eyes,
link |
and the reason we have eyes,
link |
is to communicate information about time of day
link |
to the rest of the brain and body.
link |
Remember, there's no extraocular photoreception.
link |
There's no way for light information
link |
to get to all the cells of your body,
link |
but every cell in your body needs to know
link |
if it's night or day.
link |
I talked a little bit about this in the episodes on sleep,
link |
and this episode is not about sleep,
link |
but I want to emphasize that there is a particular category
link |
of retinal ganglion cell.
link |
Remember the neurons that connect the retina to the brain
link |
that is involved in a special kind of vision
link |
that has nothing to do with conscious perception
link |
of what's around you, and it's happening right now.
link |
It's happening all the time.
link |
These are so-called melanopsin retinal ganglion cells
link |
named after the opsin that they contain within them.
link |
They are essentially photoreceptors.
link |
Remember before I said there are photoreceptors
link |
and then these ganglion cells?
link |
Well, these melanopsin cells, as the name suggests,
link |
melanopsin, have their own photoreceptor built inside them.
link |
The opsin that they contain is actually very similar
link |
to the melanopsin that is present in the skin
link |
of some amphibians, and that causes those amphibians
link |
to change their skin color in different light conditions.
link |
So you have, believe it or not,
link |
a little bit of frog skin in your eye, so to speak.
link |
Not exactly, but you essentially have the equivalent
link |
of what frogs have in their skin in your eye.
link |
Now, if you are low vision or no vision,
link |
as long as you have retinas,
link |
it's very likely you still have these cells,
link |
even though you can't see or you don't see well.
link |
These cells, retinal ganglion cells,
link |
communicate to areas of the brain
link |
when particular qualities of light are present
link |
in your environment and signal to the brain, therefore,
link |
that it's early day or late in the day.
link |
These melanopsin ganglion cells
link |
are sometimes also called intrinsically photosensitive cells
link |
because they behave like photoreceptors.
link |
What do these cells respond to
link |
and why should you care about them?
link |
Well, you should care about them
link |
because they regulate when you'll get sleepy,
link |
when you'll feel awake, how fast your metabolism is,
link |
excuse me, your blood sugar levels, your dopamine levels,
link |
and your pain threshold.
link |
There are other factors that impact those things,
link |
but they are one of the, if not the most powerful
link |
determinant of those other things,
link |
like mood and pain threshold, sleepiness,
link |
wakefulness, et cetera.
link |
These melanopsin ganglion cells have been shown
link |
by the NITZ group, N-E-I-T-Z,
link |
up at the University of Washington
link |
and by Samir Hattar's lab and David Berson's lab
link |
and a number of other people's labs,
link |
Sachin Panda, Iggy Provencio, et cetera,
link |
a number of excellent labs in neuroscience
link |
to set the circadian clock and to respond best
link |
to the contrast between blue and yellow light
link |
of the sort that lands on these cells
link |
when you view the sun, when it's at so-called
link |
low solar angle, when it's low in the sky,
link |
either in the morning or in the evening.
link |
What does all this mean?
link |
It means, and here's the first protocol,
link |
and you've probably heard me say this before,
link |
but it is appropriate to this episode to say it again.
link |
If you are not viewing the sun, sunlight,
link |
even through cloud cover for two to 10 minutes
link |
in the early part of the day
link |
when the sun is still low in the sky
link |
and doing the same thing again in the evening,
link |
you are severely disrupting your sleep rhythms,
link |
your mood, your hormones, your metabolism,
link |
your pain threshold, and many other factors,
link |
including your ability to learn and remember information.
link |
The most central and important aspect of our biology,
link |
and perhaps our psychology as well,
link |
is to anchor ourselves in time to know when we exist.
link |
Okay, it sounds a little bit abstract and philosophical,
link |
And we don't know time as a real thing
link |
because of watches and clocks.
link |
We know time at a biological level
link |
based on where the sun is and where,
link |
which of course is where we are relative to the sun
link |
because the earth is spinning around.
link |
Now, what does this mean for a protocol?
link |
It means see, get that light in your eyes early in the day
link |
and anytime you want to be awake.
link |
So try and get as much sunlight in your eyes
link |
during the day as you safely can.
link |
We'll talk about eye safety this episode in depth.
link |
And the blue light and the contrast of that blue-yellow,
link |
remember, we don't see blue.
link |
This is all subconscious.
link |
This is blue reflections coming off of sunlight.
link |
Blue light, we've been told, is so terrible for us.
link |
It is absolutely essential and wonderful
link |
for waking up the brain,
link |
for triggering all sorts of positive biological reactions,
link |
but it needs to be viewed early in the day.
link |
If you can't see sunlight
link |
because it's the thick cloud cover of,
link |
say, you're in the UK and it's winter,
link |
then artificial lights, especially blue lights,
link |
would be very beneficial to you.
link |
You need a lot of this light and its contrast with yellow
link |
in order to trigger these melanopsin cells,
link |
which would then trigger your circadian clock,
link |
which sits above the roof of your mouth,
link |
which will signal every cell in your body,
link |
including temperature rhythms, et cetera.
link |
So first things first,
link |
your visual system was not for seeing faces, motion, et cetera.
link |
The most ancient cells in your eye,
link |
which are there right now as we speak,
link |
are there to inform your body and brain about time of day.
link |
So you want to get that bright light early in the day.
link |
Absolutely essential, two to 10 minutes.
link |
You can download the light meter app
link |
if you want to measure lux.
link |
When I explained how to do that in earlier episodes,
link |
it got a little convoluted.
link |
Get that two to 10 minutes, ideally without sunglasses.
link |
Now, here's another reason to do this,
link |
and I've never spoken about this before on any podcast,
link |
which is that there have been several studies now
link |
in thousands of subjects exploring what can be done
link |
to prevent myopia, nearsightedness,
link |
and other visual defects.
link |
And it turns out in a series of large clinical trials,
link |
the conclusion has emerged that getting two hours a day
link |
of outdoor time without sunglasses, blue light,
link |
this blue light that everyone has demonized,
link |
getting that sunlight during the day for two hours,
link |
even if you're reading other things
link |
and doing other things outside,
link |
has a significant effect on reducing the probability
link |
that you will get myopia, nearsightedness.
link |
Now, whether or not that's also due to the fact
link |
that myopia can be caused by viewing things
link |
up close too much.
link |
So if you're indoors,
link |
we tend to be looking at things more closely, right?
link |
Unless you have a very large house
link |
with walls that are very far away from you.
link |
But the effect does seem to be directly related
link |
to getting sunlight
link |
and not just to the distance that you're viewing.
link |
I'm going to describe this study just briefly,
link |
but this is a second protocol.
link |
So we have one protocol about getting sunlight
link |
to set your circadian clocks, meaning wake you up,
link |
establish your sleep,
link |
will occur about 12 to 16 hours later,
link |
that's all in the sleep episode,
link |
but also to enhance your mood, to enhance your metabolism,
link |
to optimize your hormone levels,
link |
and to optimize learning and dopamine levels,
link |
this feel-good neuromodulator that's essential
link |
to not getting depressed, et cetera.
link |
But now's a second protocol, which is ideally,
link |
and this includes children,
link |
as long as they're not very small infants,
link |
ideally, we're all getting two hours of outdoor time,
link |
even if there's cloud cover.
link |
Remember, we evolved mostly under outdoor conditions,
link |
not indoor conditions.
link |
And no artificial blue light will not replace this aspect
link |
of your visual system and offsetting myopia.
link |
So I just want to briefly describe this study
link |
because it's a very important one
link |
and I don't think it's discussed often enough.
link |
There are many studies exploring this,
link |
but one of the ones I like the most
link |
looked at 693 students and a subset of them
link |
were encouraged to spend 11 hours a week outdoors, okay?
link |
So most kids are in school five days a week or so.
link |
So they're spending 11 hours a week outdoors.
link |
They are sometimes reading outdoors.
link |
They're not always just playing outdoors.
link |
They might be reading books, et cetera.
link |
They used eight different schools.
link |
And the reason they did this study,
link |
I probably should have mentioned,
link |
is that myopia, nearsightedness, is a global epidemic.
link |
At least that's how it was referred to in the study.
link |
I don't know who decides what's an epidemic or not.
link |
I think there are thresholds for that.
link |
This paper published in the journal Ophthalmology in 2018
link |
described the fact that being outdoors for two hours a day
link |
could significantly reduce the probability
link |
that these children would develop nearsightedness.
link |
And it turns out, based on other studies,
link |
that adults who spend two hours a day outside,
link |
so that would be reading outside, talking outside,
link |
no, it does not include light
link |
coming through the windshield of your car.
link |
I'll explain why in a few moments.
link |
Offset the formation of myopia.
link |
Now, myopia or nearsightedness has to do with
link |
the way that the lens focuses light onto the retina.
link |
I don't want to get into a long description of this now,
link |
but basically the lens has to bring light to the retina,
link |
not in front of it, not behind it.
link |
If it brings light to a position in front of the retina,
link |
then you won't see clearly.
link |
You will need corrective lenses.
link |
If it brings light directly to the retina,
link |
then you will see clearly.
link |
That should be intuitive why that makes sense.
link |
So you might say, why would being outside,
link |
getting this blue light or this blue-yellow contrast
link |
from sunlight actually offset myopia?
link |
Well, it probably, and I want to emphasize probably,
link |
has to do with the fact
link |
that these melanopsin ganglion cells,
link |
these intrinsically photosensitive ganglion cells
link |
are not just responsible for sleep
link |
and talking to your circadian clock and that sort of thing.
link |
They also make connections within the retina.
link |
They connect to things like, this is for the aficionados,
link |
the ciliary body, the iris, the muscles,
link |
and the structures within the eye
link |
that actually move the lens
link |
and allow you to adjust your vision to things up close
link |
And in doing so, they increase or improve the health
link |
of the little tiny muscles within the eye
link |
that move the lens.
link |
And they probably, again,
link |
this needs a little bit more work
link |
in order to really tamp down the mechanism.
link |
They're probably also involved in bringing growth factors
link |
and blood supply to the muscles and to the neurons
link |
that are responsible for this focusing mechanism
link |
So remember, your eye is an optical device.
link |
You were born with lenses.
link |
You don't have to use glasses, or maybe you do,
link |
because you have lenses in your eyes.
link |
And those lenses need to move.
link |
It's not a rigid lens like a glass lens.
link |
It's a dynamic lens and has little muscles
link |
that pull on it and squeeze it
link |
and make it thicker or thinner
link |
as you look at things close and far away.
link |
And I'll describe how that works in a moment.
link |
These melanopsin cells and their activation by sunlight,
link |
completely subconsciously, unaware, you're unaware of this,
link |
promote the health of this system within the eye
link |
and allow you to offset the myopia, nearsightedness.
link |
In other words, getting outside for two hours a day,
link |
each day, on average,
link |
even if there's cloud cover without sunglasses on,
link |
will allow you to offset the formation of myopia.
link |
Now, you might still form myopia
link |
if you have certain structural features
link |
or genetic basis for that.
link |
We will talk about things that you can do as well.
link |
But for everybody, we should be doing this.
link |
And that might seem like a lot,
link |
but this is the way that your visual system works.
link |
Staying indoors, just getting artificial light,
link |
and looking at things up close leads to visual defects, okay?
link |
It's a form of kind of like visual obesity, right?
link |
The posture of your visual system, if you will,
link |
is going to be unhealthy if you're just indoors
link |
and you're not getting sunlight early in the day
link |
and for at least two hours per day.
link |
I want to talk a little bit more about how our eyes adjust
link |
to things that are close to us or far away.
link |
This is an absolutely brilliant consequence
link |
of our nature and our design.
link |
And whenever I say nature and design,
link |
people always ask me, you know,
link |
what are you really trying to say?
link |
Are you trying to talk about creators?
link |
Are you talking about intelligent design?
link |
Look, I want to be very frank with you.
link |
I wasn't consulted at the design phase and neither were you.
link |
And so that is all very interesting,
link |
but it's not the topic of this discussion.
link |
What is clear and what is the topic of this discussion
link |
is that the eye can dynamically adjust where light lands
link |
by moving the lens and changing the shape
link |
of the lens in your eye
link |
through a process called accommodation.
link |
And if you understand this process of accommodation,
link |
you not only can enhance the health of your eyes
link |
in the immediate and long-term, but you also can work better.
link |
You'll be able to focus better on physical and mental work.
link |
You will be able to concentrate for longer.
link |
And I want to emphasize that so much of our mental focus,
link |
whether or not it's for cognitive endeavors
link |
or physical endeavors,
link |
is grounded in where we place our visual focus, okay?
link |
What we look at and our ability
link |
to hold our concentration there is critically
link |
determining how we think.
link |
So in other words, if you can hold visual focus,
link |
you can hold mental focus, cognitive focus,
link |
but holding visual focus is challenging.
link |
It's tiring because it requires movement of the lens
link |
and that movement of the lens requires activation of muscles
link |
and the activation of muscles,
link |
as you know from the physical performance episodes,
link |
if you saw them and even if you don't,
link |
is dictated by neurons.
link |
So what is accommodation?
link |
Well, it's actually very simple and very elegant.
link |
And again, this is another case
link |
where whenever I look at this stuff,
link |
even though I've been looking at it for years,
link |
learning about it for years,
link |
it still boggles my mind
link |
that we have these apparatus built into our eyes.
link |
So we have lenses in our eyes
link |
and we have these things called the irises.
link |
You're all familiar with the iris
link |
because you'll see people's pupils get bigger or smaller
link |
and we intuitively think of eyes as having the pupils.
link |
If you actually draw two circles on a sheet of paper
link |
and they look like two circles,
link |
but if you put little dots in the middle of them,
link |
they look like eyes.
link |
Your brain recognizes those as eyes
link |
because one of the first things you see
link |
when you come into this world are eyes.
link |
And actually, if you put the little dots close together,
link |
it'll look kind of wrong, like it's cross-eyed.
link |
And if you put them at different locations
link |
within those two dots, opposing locations,
link |
it'll look Google-eyed.
link |
And so your brain is actually filling in all the face
link |
and other information, even emotional information,
link |
just based on this recognition of eyes.
link |
And so there's clearly, we know this,
link |
there's real estate further up in the brain
link |
that's responsible for analyzing and recognizing faces
link |
and the eyes and the position of these little things
link |
we call irises and pupils, et cetera,
link |
is really important for how we interpret
link |
the status of others.
link |
And that's why it's such a powerful thing
link |
just to put two circles
link |
and move the pupils around on paper.
link |
In fact, I want to get into a combination,
link |
but if you think about it,
link |
if one of my pupils was up there
link |
and the other one was down there,
link |
one was really big and one was really small,
link |
that would actually be a sign of pretty severe damage.
link |
If someone gets hit hard on the side of the head,
link |
you'll notice that they shine a light in one eye.
link |
You know why they're doing that?
link |
They're actually looking at the other eye.
link |
When you shine light of the eye,
link |
that pupil constricts to limit the amount of light
link |
that comes in so it doesn't damage the eye.
link |
This also happens when you walk outside and it's bright.
link |
but we have what's called the consensual pupil reflex.
link |
There's a connection deep in the brainstem,
link |
deep back here in the brain near my neck
link |
that connects the pupil mechanism for the two eyes
link |
and they're looking at the other eye.
link |
And if you shine light in one eye
link |
and that pupil constricts, but the other one doesn't,
link |
there's a good chance there's brainstem damage.
link |
This is what they do on the side of a football field
link |
or a boxing match,
link |
or if someone unfortunately hits their head.
link |
So two pupils, and don't freak out
link |
if one pupil is a little bit smaller than the other,
link |
that doesn't necessarily mean brain damage.
link |
But if you suddenly have one pupil bigger than the other,
link |
you absolutely want to go see a neurologist right away.
link |
So the eyes and the pupils are indicative
link |
of things that are happening deep in the brain.
link |
Now, accommodation is our ability to accommodate
link |
to things that are up close here or further away.
link |
And the way this works is that the iris
link |
and the musculature and a structure
link |
called the ciliary body move the lens.
link |
So when you look far away, okay,
link |
when you see things far away, your lens actually relaxes.
link |
It can flatten out.
link |
So I want you to think about this.
link |
When you look far away,
link |
when it may be anywhere from like 20 feet away from you
link |
out to a horizon that's miles or kilometers away from you,
link |
the lens can just relax.
link |
It can flatten out.
link |
And you'll notice that it actually is relaxing
link |
to look at a horizon.
link |
It's relaxing to look far away.
link |
Whereas if I look at something up close to me,
link |
like this pen or my phone or a computer screen
link |
or this microphone, it takes effort.
link |
You'll sense the effort.
link |
Now, some of that effort is actually eye movements
link |
because you have muscles that can move your eyes
link |
within their sockets.
link |
But a lot of the work, quote unquote, is neural work
link |
of the muscles having to move and contract
link |
such that the lens actually gets thicker
link |
in order to bring the light to the retina
link |
and not to a location in front of it or behind it,
link |
so-called accommodation.
link |
There's also changes in the size of the pupil
link |
as things are closer and further away from you.
link |
In fact, there's a simple way to think about this.
link |
Healthy pupils are going to dilate
link |
when you look at something far away from you.
link |
Now, when you see something that excites you
link |
or stresses you out, your pupils also get big.
link |
Your eyes get wide.
link |
But if you look at something far away,
link |
your pupils are going to dilate.
link |
And when you look at things that are closer to you,
link |
when you move them up close,
link |
the pupils are going to shrink.
link |
That's all part of this accommodation mechanism.
link |
Now, you might say,
link |
why are you telling me about accommodation?
link |
Why are you telling me about this?
link |
Well, these days we're spending a lot of time
link |
looking at things, mainly our phones up close
link |
and computers up close, and we are indoors.
link |
If you are a young person, and even if you are 25 or older,
link |
and you are spending a lot of time
link |
looking at things up close,
link |
and you are not allowing your vision to relax,
link |
in other words, you are not giving your lens
link |
the opportunity to flatten out
link |
and for these muscles to relieve themselves of this work,
link |
you may or may not have migraine headaches.
link |
You may or may not have headaches.
link |
You might, and that could be the cause of those.
link |
But you are also training your eyes
link |
to be good at looking at things up close and not far away.
link |
And as a consequence,
link |
you are reshaping the neural circuitry in your brain,
link |
and it is not good, it is not healthy,
link |
to only look at things up close.
link |
Now, there are a lot of recommendations out there right now,
link |
especially with all the lockdowns of the last 12 to 18 months
link |
that people should look up from Zoom every once in a while,
link |
or maybe now I'm hearing that people should take calls
link |
instead of doing Zoom,
link |
or you should look up from your computer screen.
link |
It's actually not going to solve the problem
link |
just to look up from your computer screen.
link |
You need to go to a window.
link |
You need to look out at a distance.
link |
Ideally, you would even open the window
link |
because those windows actually filter out
link |
a lot of the blue light that you want during the daytime,
link |
a lot of the sunlight.
link |
It's actually 50 times less gets through.
link |
You want to get out onto a balcony.
link |
You want to relax your eyes and look out at the horizon.
link |
You want to go into what's called panoramic vision
link |
and let your vision expand.
link |
You want this lens mechanism to be very elastic.
link |
You don't want it to get stuck in that configuration
link |
of looking at things up close.
link |
Accommodation is a wonderful feature of your visual system,
link |
but you don't want to push that too hard,
link |
too often or for too long.
link |
You want to view the horizon.
link |
You want to get outside,
link |
not just to lighten the load on your mind
link |
or to think about other things,
link |
but to maintain the health of your visual system.
link |
In other words, you want to exercise these muscles
link |
and that involves both the lens moving
link |
and getting kind of thicker and relaxing that lens.
link |
And the relaxation of the lens
link |
is actually one of the best things you can do
link |
for the musculature of the inner eye.
link |
So what's the protocol?
link |
How often should you do this?
link |
You might be surprised,
link |
but for every 30 minutes of focused work,
link |
you probably want to look up every once in a while
link |
and just try and relax your face and eye muscles,
link |
including your jaw muscles,
link |
because all these things are closely linked
link |
in the brainstem and allow your eyes
link |
to go into so-called panoramic vision,
link |
where you're just not really focusing on anything
link |
and then refocus on your work.
link |
At least every 90 minutes of looking at things up close,
link |
or even if you're looking at a screen,
link |
a television screen or you're watching a movie
link |
or you're indoors, for every 90 minutes of that,
link |
you ideally would have at least 20,
link |
probably more like 30 minutes of being outside, ideally,
link |
but if you can't be outside, of non up close vision.
link |
Now you might say, that's impossible.
link |
How am I supposed to do that?
link |
I'm in an office or I'm in a building.
link |
Get to a window, get outside if you can do it safely,
link |
get onto a balcony and just let your eyes relax.
link |
Many people are experiencing severe vision problems
link |
because they're not getting enough sunlight during the day.
link |
They have sleep problems
link |
because they're not viewing sunlight early in the day.
link |
And as I've mentioned in previous episodes,
link |
they're getting a lot of artificial stimulation,
link |
artificial light stimulation of the eye
link |
in the middle of the night.
link |
All of this is through the visual system.
link |
So migraines, fatigue,
link |
challenges with your eyesight getting worse as you age,
link |
or even in young people there's a, you know,
link |
at least according to the articles,
link |
they described it as this epidemic of myopia
link |
can largely be dealt with by getting outside,
link |
going into panoramic vision,
link |
experiencing some distance division,
link |
look at things off on the horizon.
link |
If you're walking or hiking or biking,
link |
not looking at your phone the whole time
link |
that you're doing that.
link |
If you're at the bus stop or you're commuting,
link |
certainly not looking at your phone
link |
the entire time you're doing that.
link |
And I want to emphasize another protocol,
link |
although I don't want to get into it in too much depth,
link |
because I want to make sure that I also talk about
link |
a number of other important aspects of the visual system
link |
that are more related to sight.
link |
But getting into optic flow is very important
link |
for de-stressing your system.
link |
When you move through space,
link |
whether or not it's through walking, biking, even swimming,
link |
if it's self-generated optic flow,
link |
so probably not driving or motorcycling,
link |
but yes, bicycling or, I don't know, unicycling.
link |
I don't know why I thought about unicycling.
link |
There used to be a graduate student at Stanford
link |
who was a really impressive unicycler.
link |
Those are pretty rare.
link |
As long as it's self-generated optic flow,
link |
meaning you're generating motion of your body
link |
and the visual images around you are passing by
link |
on your eyes, that is very good for the visual system.
link |
And it's very good for the mood systems
link |
and the neuromodulator systems of the brain and body
link |
that regulate mood.
link |
This is well-established.
link |
So I'm not telling people to get away
link |
from their phone and their computers.
link |
I spend a lot of time staring at a page,
link |
drawing, writing, texting, et cetera, just like you do.
link |
But we're really talking about some very simple protocols
link |
that aren't just designed to improve your sleep,
link |
but are really designed to bolster and enhance your vision.
link |
And of course, because it's this podcast,
link |
we will also talk about things that you can take
link |
to improve your vision.
link |
But if your visual behavior isn't right,
link |
and I do believe we should always start with behaviors
link |
and then think about nutrition, supplementation, et cetera.
link |
If your behaviors around vision aren't right,
link |
you cannot expect to have good, healthy eyesight
link |
for a long time, meaning throughout your lifespan.
link |
And if your vision is already poor,
link |
many of these things that I'm talking about today,
link |
perhaps all of them, will improve your vision
link |
And if your vision is starting to go,
link |
then doing these behaviors is likely
link |
to really enhance the quality of the vision
link |
that you will build and maintain over time.
link |
And all of these are essentially zero cost, okay?
link |
If you live in a very dark environment,
link |
like a cave or outer space,
link |
it's going to be hard to do some of this stuff.
link |
But if you're on planet earth, even if there's cloud cover,
link |
chances are you can do some or most,
link |
or even all of these, some, most, or all days.
link |
What I'm about to describe next is going to seem so silly
link |
on the face of it, but has deep mechanism to support it.
link |
Put simply, when you get tired, your eyelids close.
link |
And when you're alert, your eyelids are open.
link |
That is because you have neurons in your brain
link |
that depending on your level of alertness
link |
will make it easy or hard to keep your eyes open.
link |
Now that's a complete duh,
link |
except that we don't often think about the relationship
link |
between alertness and where we are looking and our eyelids.
link |
Now, I learned this from a colleague of mine in psychiatry
link |
who happens to work on hypnosis.
link |
I'm not going to hypnotize you right now.
link |
That's actually for a future episode.
link |
But what happens when we get tired?
link |
Our eyelids close and our chin moves down.
link |
We tend to nod out this way.
link |
If you have ever been in a classroom,
link |
certainly not one of mine,
link |
but if you've been in a classroom
link |
and the lecture is kind of drawing on or it's the afternoon,
link |
what you'll notice is that a number of students,
link |
their heads are kind of,
link |
their eyelids are closing and their chin is dropping.
link |
And then you'll see a bunch of heads balancing back up.
link |
I was definitely one of those people in class.
link |
If it was post-lunch in the afternoon, it's warm,
link |
the hum of the air conditioner or whatever it is,
link |
and I just out, okay?
link |
When we're wide awake, the opposite happens.
link |
Our eyelids are open all the way
link |
and our chin happens to be up.
link |
And no, this is not me telling you to have good posture.
link |
However, what I learned from my colleague at Stanford
link |
is that these circuits actually act in loops.
link |
maybe it's because these melanopsin cells
link |
are in the bottom of our retina, they are.
link |
And maybe it's because they're there
link |
in order to view sunlight, which is overhead, which it is.
link |
But that system of alertness
link |
is linked to the position of our eyes.
link |
So when we look up and our eyelids are up,
link |
it actually has a purpose.
link |
It actually creates a wakefulness signal for the brain.
link |
And so while this might seem like the silliest
link |
and simple tool that I might ever describe on this podcast,
link |
if you are feeling tired,
link |
it actually can be beneficial
link |
to the wakefulness systems of the brain,
link |
including the locus coeruleus
link |
and these areas that release norepinephrine,
link |
to actually look up, to actually look up toward the ceiling.
link |
You don't want your chin all the way back,
link |
but to look up and to raise your eyes toward the ceiling
link |
and to look up and try and hold that for 10 to 15 seconds.
link |
So this isn't looking up and closing your eyes
link |
like on a nice sunny day, that's relaxing.
link |
This is looking up and actually looking up at the ceiling.
link |
It actually triggers some of the areas of the brain
link |
that are involved in wakefulness.
link |
So if you're somebody who's falling asleep at your work,
link |
this can be very beneficial.
link |
Likewise, many people are looking at their phone all day
link |
and their chin is down,
link |
and then they're sitting at a computer
link |
that's positioned below them
link |
and they're having trouble staying awake or focusing.
link |
It can be very bad.
link |
I tell Costello this all the time
link |
because he's always falling asleep
link |
while he's trying to do his work.
link |
Positioning your computer screen up at eye level
link |
or sometimes having it actually above eye level
link |
can actually create wakefulness and alertness
link |
for the work that you're going to do.
link |
This is simply because of this connection
link |
between the brainstem circuits and the other neural circuits
link |
that control wakefulness and eyelids opening and looking up.
link |
Okay, so again, it's remarkably simple,
link |
almost laughably simple,
link |
but it's grounded in some of the most hardwired,
link |
meaning present from birth aspects of our neural circuitry.
link |
And norepinephrine released from locus coeruleus
link |
isn't just a mouthful.
link |
It's a really interesting and powerful mechanism
link |
for how the rest of the brain wakes up.
link |
Locus coeruleus hoses the rest of your brain
link |
with norepinephrine in order to wake up those circuits
link |
for work and attention.
link |
And so eyes up is actually a way,
link |
a route into increased alertness.
link |
Eyes down is a route into sleepiness,
link |
into reduced alertness.
link |
And I have only one friend that texts up here,
link |
like on the street, holds his phone up here.
link |
It looks ridiculous.
link |
And yet, you know, if we were trying to create
link |
more sense of alertness, if that's your goal,
link |
positioning computer screens up high, chin up,
link |
looking up if you need to kind of create
link |
an alertness signal, not always being chinned down
link |
and texting or working into typewriters or reading below us
link |
is actually going to send a recurring wakefulness signal.
link |
When things are up, we tend to be alert.
link |
When everything's focused down, including our eyes,
link |
it tends to have a more suppressive or sedative type
link |
signaling to the deeper centers of the brain.
link |
Now, before we move on to the science and tools
link |
and protocols related to pattern vision,
link |
I want to mention another study that was done
link |
by the University of Pennsylvania.
link |
They have a terrific group there that works on sleep
link |
that made an important discovery
link |
that I think everybody should know about,
link |
which is that children that sleep in rooms
link |
that have a nightlight or dim lights
link |
are much more likely to develop myopia, nearsightedness.
link |
Conversely, children that sleep in very dark rooms,
link |
so either very dim nightlights or a complete black,
link |
they have a much lower, statistically speaking,
link |
a significantly lower probability
link |
of developing myopia, nearsightedness.
link |
It's because the wavelengths of light that matter
link |
for these melanopsin cells
link |
oftentimes can get through the eyelids.
link |
And that's particularly true for children
link |
and people that have thin eyelids.
link |
Some people, like me, have very thin eyelids.
link |
I've been told this before.
link |
Not many people touch my eyelids,
link |
but among those that have, they have very thin eyelids.
link |
I notice I have very thin eyelids compared to, say, Costello.
link |
Now, Costello's eyes droop.
link |
He can't even close his eyes all the way.
link |
They're so droopy.
link |
But many people have thin eyelids,
link |
and those people are going to be even more prone
link |
to light coming in through the eyelid.
link |
So for parents, for kids, and for adults,
link |
you really want to try to get to a place
link |
where you can sleep in a completely black
link |
or dark environment.
link |
One little exposure to light, no big deal.
link |
But this ties back to the other protocol
link |
that I've described before in the mood and sleep episodes,
link |
which is that viewing light, even a very low intensity,
link |
between the hours of 10 p.m. and 4 a.m.,
link |
it's extremely detrimental to the dopamine
link |
and other mood-producing systems of the brain.
link |
It can negatively impact learning and immunity
link |
and even blood sugar and make people type 2 diabetes prone
link |
by way of communication from these melanopsin cells
link |
to a structure in the brain called the habenula.
link |
Why am I throwing out all this verbiage?
link |
Well, because people have asked for more mechanisms.
link |
So if you really want to know when you look at blue light
link |
or if blue light is getting in through your eyelids
link |
in the middle of the night,
link |
it is likely distorting these lens accommodation mechanism
link |
in the eye and leading to myopia in some cases.
link |
So that's one reason to avoid blue light exposure
link |
and bright light exposure,
link |
even nightlight exposure in the middle of the night.
link |
Viewing any light of bright intensity
link |
between the hours of 10 p.m. and 4 a.m.
link |
on a consistent basis is going to suppress dopamine
link |
because of the way that that light activates
link |
these melanopsin cells and the habenula
link |
and the dopamine system.
link |
So it's all very simple.
link |
Get as much bright light as you can safely, right?
link |
You never want to look at any light so bright
link |
that it's painful to look at during the daytime.
link |
Try and go without sunglasses unless you need them.
link |
Now I wear sunglasses for sake of sport
link |
and sake of when it's really bright out,
link |
but I try to get two hours a day of working outside
link |
or being outside, even if there's cloud cover,
link |
that's going to offset myopia.
link |
It's going to help you get better sleep.
link |
It's going to support mood and metabolism, et cetera.
link |
And at night, if you're sleeping with a lot of lights
link |
in the room, and especially if there are kids
link |
that need a nightlight,
link |
you should try and wean them off that nightlight
link |
because it's going to be beneficial for their vision
link |
to wean them off that nightlight
link |
and put them into a darker environment.
link |
Obviously you want to get them emotionally comfortable
link |
Now let's talk about pattern vision,
link |
actual seeing things like faces and colors, et cetera.
link |
I'm presuming that some of you out there are colorblind.
link |
We can all help the red-green colorblind folks out there.
link |
By not using red in slides and diagrams and on menus
link |
and things of that sort, try and use magenta instead.
link |
They can see the contrast between magenta and green better
link |
than if there's red and green.
link |
So be kind to the colorblind folks out there.
link |
It's actually a fair percentage.
link |
And there are a lot of different kinds of colorblind.
link |
I should just mention some people are true monochromats.
link |
They see the world in black and white.
link |
That's exceedingly rare.
link |
Most colorblind people, colorblind in quotes,
link |
are red-green colorblind,
link |
meaning they lack red cone photopigment,
link |
meaning they can't see long wavelengths of light.
link |
So they see the world much as a canine or a cat does
link |
where they don't get the green-red contrast.
link |
That's where we call it red-green colorblind.
link |
They have the green cones,
link |
but they can't do the contrast comparison
link |
that I described at the beginning of the episode.
link |
So use magenta and they will be able to see things.
link |
You wonder why stop signs and stop lights
link |
and things aren't in magenta.
link |
Well, because the world is unkind
link |
to the red-green colorblind individuals
link |
and they have to learn the position
link |
of those lights in the street lights
link |
and they have to learn the shapes of signs,
link |
which they can do readily
link |
and it usually says stop on it as well.
link |
But if you care about colorblind folks, which I do,
link |
then we could all do them a service by,
link |
I think by law actually in the US,
link |
menus are required to be colorblind accessible.
link |
How can you improve your vision?
link |
How can you get better at seeing things?
link |
Well, one way is to make sure that you spend
link |
at least 10 minutes a day total,
link |
at least, viewing things off in the distance.
link |
So that would be well over half a mile or more.
link |
Try and see a horizon,
link |
try and get your vision out to a location
link |
that's beyond the four walls of your house or apartment
link |
or the doors of your car and the windshield of your car.
link |
I know that can be hard to do, but it's very valuable.
link |
If you live in a city like New York
link |
and it's skyscrapers everywhere,
link |
you've probably experienced
link |
the incredible sense of relaxation.
link |
And it's aesthetically beautiful
link |
when you are walking down one of these long avenues
link |
and I think they have a name for this in New York,
link |
where the sunset is suddenly visible
link |
along a long avenue between some skyscrapers.
link |
And it's just very relaxing
link |
to be able suddenly to see at a distance.
link |
And that's actually because this eye mechanism
link |
relaxing the lens and relaxing some of the musculature
link |
around the eyes send signals deep into the brainstem
link |
that release some of the centers
link |
that are involved in alertness, AKA stress.
link |
And it's very pleasant for a reason.
link |
It's not a placebo effect, if you will.
link |
There are a bunch of neurochemicals
link |
and things that are associated with that.
link |
So try and see at a distance
link |
because it's good for your eyesight.
link |
It'll keep this lens nice and elastic
link |
and the muscles nice and strong
link |
that move the lens.
link |
And it has this relaxing component to it.
link |
Now, our visual system is exquisitely tuned to motion,
link |
not just our self-generated motion,
link |
but the motion of things around us.
link |
And one of the things that it does
link |
is something called smooth pursuit.
link |
Smooth pursuit is our ability
link |
to track individual objects moving,
link |
as the name suggests,
link |
smoothly through space in various trajectories.
link |
You can actually train or improve your vision
link |
by looking at smooth pursuit stimuli.
link |
And that sounds really boring.
link |
What you can do is,
link |
and I'll provide a link to some that I think are pretty good
link |
that are used in various clinics,
link |
ophthalmology and optometry clinics.
link |
You can actually take a few minutes each day,
link |
or maybe if you don't do it each day,
link |
you could do every third day or so,
link |
and actually just visually track a ball.
link |
Sometimes it's moving in and kind of an infinity symbol.
link |
Sometimes it's more of a sawtooth.
link |
Sometimes it's changing speed.
link |
Sometimes the cue that you're following,
link |
the little target, is dilating and contracting.
link |
This is going to keep the muscles,
link |
I want to be clear,
link |
this is going to keep the extraocular muscles
link |
conditioned and strong
link |
and allow you to have a healthy smooth pursuit system.
link |
Remember, the brain follows the eye.
link |
It follows the movements of the eye.
link |
It has to deal with that.
link |
And the neural circuits within the brain have to cope
link |
with changes in smooth pursuit.
link |
So if you're doing a lot of reading up close,
link |
you're not viewing horizons,
link |
you're not getting a lot of smooth pursuit type stimulation
link |
or you're just getting it within the confines
link |
of a little box on your phone,
link |
like your smooth pursuit is over millimeters
link |
or what we always talk in terms of visual angle,
link |
but the amount of degrees of visual angle.
link |
But if you're just looking at smooth pursuit
link |
in this little tiny box on your phone
link |
or on your computer screen,
link |
and you're not looking at objects in your environment,
link |
like swooping birds and things like that,
link |
which I'm guessing many of you
link |
are not spending your time doing,
link |
well, these mechanisms for smooth pursuit
link |
will get worse over time.
link |
Your vision will get worse.
link |
And so while I prefer that people get out
link |
into the real world and experience
link |
smooth pursuit tracking of visual objects,
link |
and maybe it's a good reason to go to a hockey game
link |
or try and keep your eye on the puck,
link |
which I can never seem to do, move so fast,
link |
or I guess this is a good reason to watch live sports
link |
if that's your thing,
link |
or watch a tennis match like a cat, like a kitten,
link |
watching the ball go back and forth.
link |
Whatever, watching kids play, it doesn't really matter.
link |
The idea is that you want to use the visual system regularly
link |
for what it was designed for,
link |
and smooth pursuit is a great way
link |
to keep the visual and motion tracking systems
link |
of the brain and the eye and the extraocular muscles
link |
working in a really nice coordinate fashion.
link |
I would say five to 10 minutes, three times a week,
link |
will be great if you care about your vision,
link |
you can train your vision in this way.
link |
The other one is to train accommodation.
link |
There are a lot of videos out there,
link |
I want to be clear, on the internet,
link |
some of which are from clinicians, some of which are not,
link |
some of which are from scientists,
link |
some of which are from other sources,
link |
talking about things you can do to make your vision better,
link |
to improve your vision.
link |
Most of those are geared toward improving
link |
the extraocular eye muscles,
link |
but I did consult with our chair of ophthalmology
link |
at Stanford School of Medicine, Jeff Goldberg,
link |
who's an MD and a PhD, a phenomenal scientist
link |
and a phenomenal clinician,
link |
and incidentally, a phenomenal chairman as well,
link |
about what sorts of things,
link |
tools are actually beneficial for pattern vision and sight,
link |
because there's just so much out there on the internet,
link |
not all of which is accurate or good, frankly.
link |
And he agreed that a smooth pursuit stimulus,
link |
that kind of training, as well as, or exercise,
link |
as well as near far.
link |
So spending a few minutes,
link |
you might even just do this for two minutes
link |
of looking at something up close,
link |
that's going to activate these accommodation mechanisms
link |
and then moving it at arm's length
link |
and focusing on it for five, 10 seconds,
link |
maybe more, maybe 15 or 20 seconds,
link |
then slowly moving it into a location and then out.
link |
This is actually a lot like the visual training
link |
that's done post-concussion to try and repair
link |
actually repair some of the balance and motor
link |
and visual and cognitive aspects of the brain.
link |
And we are going to have a guest on in a future time
link |
to deal with concussion and some post-concussion training.
link |
A lot of post-concussion recovery and training
link |
centers around the visual system,
link |
not just because people are trying to recover their vision
link |
and their sense of balance,
link |
but because, as I mentioned earlier,
link |
the brain's ability to make sense of its environment
link |
and the brain's ability to parse time,
link |
not just on the day-night schedule,
link |
but also shorter time intervals follows the visual system.
link |
Something we'll turn to a little bit more at the end.
link |
So what does this mean?
link |
The tool is spend two to three minutes doing smooth pursuit.
link |
There's some programs on YouTube.
link |
You can just look up smooth pursuit stimulus
link |
and I'll provide a link to a couple I like as well.
link |
You could do this with a pen if you wanted.
link |
You could do this, someone else could hold a wand
link |
and you could do that
link |
if you've got someone that can do that for you.
link |
Practice accommodation for a few minutes,
link |
maybe every other day, just bringing something in close.
link |
You'll feel the strain of your eyes doing that.
link |
I can feel it right now.
link |
You'll feel a relaxation point.
link |
Move it past that relaxation point
link |
where you will have to do what's called a virgin side
link |
movement to maintain focus on that location
link |
as it moves out, bring it back in.
link |
At the point where you actually have to go cross-eyed,
link |
this will differ for different people
link |
depending on how far apart your eyes are,
link |
so-called interpupillary distance.
link |
So for me, I have been teased before,
link |
I have a very short interpupillary distance.
link |
I'm not a cyclops, but I'm heading there.
link |
Some people are more wall-eyed like a flounder.
link |
Well, depending on your interpupillary distance,
link |
the point at which things get blurry
link |
and cross-eyed will vary.
link |
But for me, as I get about, oh gosh,
link |
I guess it's about six inches from my nose,
link |
it's really hard, I can't accommodate any longer.
link |
I move it out another inch and everything's in nice focus.
link |
Try and see whether or not you can get things closer.
link |
Now you don't want to get cross-eyed.
link |
Remember what your parents told you,
link |
or my parents told me that if you cross your eyes
link |
when you're young, that they can stay that way.
link |
Actually, they won't necessarily stay that way,
link |
but your brain can start losing information
link |
and the ability to see binocular depth,
link |
something we'll talk about in a moment.
link |
But for now, the protocol would be two to three,
link |
maybe five minutes, just practice that,
link |
practice accommodation,
link |
and then be sure to give your eyes some rest.
link |
Get outside, look at a horizon or do nothing,
link |
just kind of let your eyes go soft.
link |
I guess what the yogis would call soft gaze,
link |
just kind of relax your eyelids,
link |
not this, not eyes closed, just relax.
link |
Panoramic vision, try and see the walls around you
link |
without moving your head.
link |
Exercise your eye muscles,
link |
exercise the accommodation mechanisms of your eyes.
link |
Practice a little bit of smooth pursuit.
link |
You don't have to be neurotic about this,
link |
but if you do this often enough,
link |
meaning every other day, every third day or so,
link |
you can be the strange person on the plane
link |
or in the classroom doing this.
link |
People might chuckle or look at you funny or tease you,
link |
but that's okay because you'll be able to see
link |
when they are losing their vision,
link |
so you'll get the last laugh.
link |
Please don't laugh at them,
link |
but maybe you can help them at that point.
link |
You can hold the pen for them.
link |
It's really worth preserving your vision.
link |
And again, if you're a young person, this is great
link |
because then you can actually build
link |
an extra strong visual system
link |
using all the tools that we're describing.
link |
I do want to talk about a new set of findings
link |
that are related to red light
link |
and offsetting age-related macular degeneration.
link |
There are a lot of ways in which our visual system
link |
gets worse over time,
link |
but one is so-called age-related macular degeneration.
link |
Glenn Jeffrey at the University College London,
link |
somebody I've known for decades because he's a scientist,
link |
has done beautiful work on development
link |
and function of the visual system,
link |
has published a number of papers recently.
link |
One that got a particularly high amount of attention
link |
in the press was one that showed that flashing red light
link |
into the eyes early in the day, not late in the day,
link |
early in the day can help offset
link |
some age-related macular degeneration,
link |
presumably by enhancing the mitochondrial function
link |
in the photoreceptors.
link |
There does seem to be some evidence for that,
link |
although it's still early days.
link |
I want to emphasize you don't want to shine
link |
really bright lights into your eyes.
link |
You never want to look at any light that's so bright
link |
that it's painful,
link |
and you never want to force your eyelids to stay open.
link |
If you need to close your eyes in order to be comfortable,
link |
well, then chances are that light is too bright.
link |
But doing just a couple minutes a day,
link |
like two minutes a day of flashing this red light
link |
into one eye and then the other,
link |
as long as it was early in the day before noontime,
link |
and as long as it was in individuals
link |
that were 40 years or older,
link |
did seem to have a significant effect
link |
in offsetting some of the age-related macular degeneration
link |
that would otherwise occur.
link |
Again, these are early findings.
link |
If you want to do this, please be careful.
link |
Please talk to your optometrist and or ophthalmologist.
link |
Your eyesight is precious.
link |
You don't want to damage it, but it is interesting,
link |
and it does seem like red light
link |
can improve the function of the mitochondria.
link |
These photoreceptors have a lot of mitochondria,
link |
the energy-producing organelles within the cells,
link |
because they are some of the most metabolically active cells
link |
in your entire body.
link |
Your photoreceptors are active all the time
link |
as you're looking around,
link |
and even when your eyes are closed, they're active.
link |
In fact, through a weird twist of the biology,
link |
and please look this up if you're really interested in this,
link |
your photoreceptors are actually most active in the dark.
link |
It's a twist of biology, the way the system's arranged,
link |
that when light comes on, they shut off their activity.
link |
So actually, whether or not you see something in front of you
link |
like this pen or my face
link |
is because the way your photoreceptors are turning off,
link |
not turning on, it's a really cool twist,
link |
and I don't want to go too far down that rabbit hole,
link |
If you're interested in how photoreceptors work,
link |
it's an absolutely incredible literature.
link |
Just Google, excuse me, look up on the web.
link |
We are not partial just to Google.
link |
I happen to use Google, but use your web browser
link |
to look up a photoreceptors hyperpolarization site,
link |
and you can learn a lot about that
link |
if you're a real nerd for the stuff like I am.
link |
Okay, so red light to the eye can perhaps, it seems,
link |
help maintain vision, doing smooth pursuit exercises,
link |
and accommodation, near-far exercises.
link |
Some people suffer from poor eyesight
link |
simply because their eyes get dry.
link |
There are incredible, believe it or not,
link |
lubricating mechanisms for the eye,
link |
not just tears, but thin sheet of oil.
link |
I mean, it's just amazing.
link |
Unless you have some sort of corneal abrasion,
link |
the cornea is the clear stuff on the outside of your eye,
link |
corneal abrasion, when you blink, it's smooth.
link |
You don't feel it.
link |
It's just really, really smooth,
link |
and yet if you've ever had a corneal scratch,
link |
I've had this, it's really rough.
link |
You have a ton of pain receptors in the cornea.
link |
The lubrication of the cornea is supported by blinking,
link |
and while it seems a little silly,
link |
some people actually benefit from doing, you know,
link |
some, you know, five or 10 or 15 seconds of blinking,
link |
and then doing their focused work.
link |
Some people, their eyes are drying out,
link |
because as we focus, if we're trying to do something,
link |
our eyelids stay open, the eyes can dry out,
link |
but it also can make it such
link |
that when we blink the next time,
link |
there's a kind of a need to focus,
link |
because there's some distortions in these oils and liquids
link |
across the corneal surface.
link |
If you're somebody who suffers from dry eye,
link |
I do hope they'll find a treatment or a cure for dry eye
link |
soon, there isn't one at present.
link |
Someone stands to make a lot of money out there.
link |
If you can find a cure for dry eye,
link |
let the companies know or start a company.
link |
Right now, it's still a mystery as to how to do that,
link |
but blinking for five to 15 seconds,
link |
probably slowly, not as quickly as I'm doing here on video,
link |
but just, you know, maybe a blink every second or two
link |
for 15 seconds can lubricate the eyes,
link |
and that's not directly related to anything neural,
link |
it's just going to allow the optics of your eye to be clear,
link |
just like when the screen of your phone gets dirty,
link |
like when Costello is texting on my phone
link |
and I pick it up and it's like covered with smudge,
link |
to clean it off in order to see things clearly,
link |
the same thing is happening for these optical devices
link |
on the front of your brain.
link |
Remember, these are brain.
link |
Okay, so a lot of protocols today, almost all of them.
link |
Behavioral protocols.
link |
I do want to talk a little bit more about vision
link |
and how it works internally,
link |
and then I also want to talk about
link |
some of the foods and supplements
link |
that have been shown to support vision
link |
and offset visual loss,
link |
and maybe even reverse some visual loss.
link |
Let's talk about binocular vision and lazy eye.
link |
I'm very familiar with lazy eye because when I was a kid,
link |
I went swimming one day, one day,
link |
and I didn't have my goggles,
link |
and so something must have been happening, as I recall,
link |
with the eye moving down through the water.
link |
I've always had this problem
link |
that I can only do the freestyle stroke off to one side.
link |
The people I swim with are always laughing.
link |
Somehow I kind of move toward drowning
link |
when I try and breathe on the right side.
link |
I think there's some asymmetry in the way I'm organized.
link |
Anyway, I was off to my left
link |
and my eye kept going in and out of the water,
link |
and there was chlorine in the water,
link |
and it was making my eye uncomfortable,
link |
so I just closed my eye.
link |
I just decided, you know,
link |
I knew more or less how to swim straight-ish.
link |
Might've bounced off the lane lines a few times,
link |
but I just used the other eye
link |
to kind of steer for that mark on the wall.
link |
Got out of the pool, took a shower, dried off,
link |
and then completely lost binocular vision for three days.
link |
The young brain up until about age seven,
link |
but maybe even extending out until about age 12,
link |
is extremely vulnerable to differences
link |
in ocular input between the two eyes.
link |
My scientific great-grandparents won the Nobel Prize
link |
for discovering so-called critical periods.
link |
Periods of time in which the brain is more plastic,
link |
more able to change.
link |
Those two guys, David Hubel and Torrance Wiesel,
link |
thank you, David and Torrance,
link |
forever changed the face of visual neuroscience
link |
and forever changed the way we think about treatment
link |
of the young brain.
link |
It used to be thought that you wouldn't want to do a surgery
link |
on a young kid because of risk of anesthesia
link |
in young individuals,
link |
but we now know that you need to repair these imbalances
link |
that even a few hours, okay, I don't want to scare anybody.
link |
I'll talk about reversal, but a few hours
link |
of occluding one eye early in life can lead to permanent,
link |
unless something's done, permanent changes
link |
in the way that the brain perceives the outside world,
link |
such that when that eye is opened up again,
link |
the brain actually can't make sense
link |
of anything that's coming through it.
link |
It shuts down that visual pathway somehow.
link |
So what happened to me was I actually was, my eye was fine.
link |
I got out of the pool, I opened my eye,
link |
but I couldn't see through that eye.
link |
Everything was blurry, double vision,
link |
unless I covered this eye
link |
and then I could see perfectly fine.
link |
Fortunately, I went to an ophthalmologist
link |
who understood the literature.
link |
Thank you, Dr. Mark Lurie, who understood the literature
link |
and made it clear that what I needed to do
link |
was to occlude the other eye,
link |
the eye that was working very well.
link |
Clearly he understood the work of Hubel and Wiesel.
link |
Now, again, you don't want to start playing games
link |
with this kind of stuff when you're a kid.
link |
If you wear, let's say you have a Halloween costume
link |
and you wear an eye patch,
link |
you're a pirate or something for Halloween
link |
and you cover it up on one side,
link |
probably for the night of Halloween, it's okay.
link |
I do not recommend doing that recreationally
link |
if you don't need that if you're a young child
link |
or for your child to do that,
link |
because indeed you create imbalances in the brain machinery
link |
that compares information coming in through the two eyes
link |
and it can shut down the neural information
link |
for the occluded, the closed eye.
link |
Now, I was able to reverse this issue,
link |
but my binocular vision has never been terrific.
link |
I'm much better at the dartboard and still not very good.
link |
If I close one eye, I'm much better at the pool table.
link |
If I close one eye and I still am terrible.
link |
I was the kid in the outfield,
link |
the ball's coming towards me, the ball's coming towards me,
link |
I'm going to catch the ball
link |
and like a hit me square in the lip.
link |
My binocular vision isn't great
link |
as a consequence of this early event.
link |
And I have a hard time with those binocular stereograms,
link |
those images that are kind of,
link |
you're supposed to look at them
link |
and then the binocular depth image like pops out.
link |
All the other kids were going, oh, there's the whatever,
link |
the Statue of Liberty, there's the American,
link |
So I have binocular vision, but I use other cues.
link |
I use the near far cues that I talked about before,
link |
motion parallax, the fact that things are closer to me
link |
or moving faster than things further away
link |
in order to judge depth.
link |
And years later when I got involved in,
link |
and I don't suggest this for most people,
link |
I got involved in boxing and martial arts
link |
when I was younger.
link |
Sometimes we'll see fighters,
link |
this is a slip to avoid getting punched.
link |
It's also generating motion parallax.
link |
Many animals judge depth by moving their head,
link |
not by using other mechanisms of accommodation, okay?
link |
So a lot of birds and monkeys and animals
link |
will judge depth by moving their head like this,
link |
or they'll move from side to side.
link |
Animals that will undulate sometimes
link |
are actually doing a depth measurement
link |
because as you move from side to side,
link |
the brain is able to do the math of depth.
link |
So what does this all mean in terms of protocols?
link |
If you're a young person,
link |
do your best to get really good binocular vision,
link |
not just at level of your phone or your tablet,
link |
but also at distance.
link |
You will build strong binocular visual machinery
link |
in the brain and at the level of the eyes
link |
and the eye musculature.
link |
Now, if you're somebody who did have an occlusion,
link |
what's needed is to cover up the other eye
link |
to create an imbalance so that the weak eye,
link |
the so-called lazy eye,
link |
this is sometimes referred to as amblyopia,
link |
that eye has to work harder.
link |
So for me, they patched this other eye and made this eye,
link |
eventually I got vision through that eye back,
link |
then they opened them both up.
link |
Now, you might ask,
link |
what happens if you cover both eyes early in life?
link |
And this is where it gets interesting.
link |
You might think, well,
link |
if covering one eye leads to poor vision for that eye
link |
after that eye is open,
link |
covering both eyes will probably make you blind, right?
link |
Actually, that's not what happens.
link |
What Hubel and Wiesel discovered
link |
and what's been affirmed many, many more times over
link |
in subsequent studies
link |
is that it's competitive,
link |
that the two eyes are competing
link |
for real estate up in the brain.
link |
So if you actually cover both eyes,
link |
you actually extend the period of critical plasticity.
link |
This is a really interesting aspect
link |
that other people are starting to leverage now
link |
in terms of how to reopen plasticity later in life.
link |
But please don't go around
link |
with your eyes covered for too long.
link |
There are some like retreats and stuff
link |
where people go into caves with absolutely no vision.
link |
It creates hallucinations.
link |
We'll talk about why that is in just a moment.
link |
But here's my suggestion.
link |
Try and get balanced visual input through the two eyes.
link |
Almost everybody has a dominant eye.
link |
It usually doesn't relate to your dominant hand,
link |
And so for me, if I cover up my right eye,
link |
I see much less well, much more poorly.
link |
It's a little bit fuzzy
link |
and I have to work harder
link |
in order to see the camera, for instance.
link |
Then if I cover up my left eye,
link |
it's actually really easy for me to relax.
link |
I have a dominant eye.
link |
Yeah, you can balance that out
link |
by covering up the dominant eye a little bit each day.
link |
But I would warn any young people,
link |
meaning 12 or younger,
link |
against creating these imbalances
link |
if there isn't a clinical need to do that.
link |
And if you do have strong imbalances between the two eyes,
link |
which can be caused by cataract and lens issues,
link |
can be caused by neuromuscular issues, et cetera,
link |
to try and get those dealt with as early as possible
link |
by contacting a really good ophthalmologist
link |
and ideally a neuro-ophthalmologist.
link |
It is very normal.
link |
I should say it's very common for young children, babies,
link |
to have an eye with strabismus
link |
that either deviates out or that deviates in.
link |
It is important to correct that
link |
if you would like to have balanced vision
link |
between the two eyes
link |
and for the brain to respond equally to the two eyes
link |
and to have, I would say, high-fidelity quality vision.
link |
Although some people who have an eye
link |
that drifts can function normally in life,
link |
you have an opportunity early in life to rescue that.
link |
Well, maybe I will do this,
link |
but I can actually relax this eye.
link |
It's so weak in some cases
link |
that it actually can start to deviate.
link |
Here, I'll just do this here.
link |
It's not crossing my eyes.
link |
So I actually can move my, I can misalign my eyes
link |
because I have to fight very hard
link |
to have the musculature for this eye,
link |
keep that eye aligned with the other eye.
link |
And that's because I've been doing eye exercises
link |
since I was in my 20s
link |
because I noticed when I would study a lot,
link |
this eye would start to drift in.
link |
I'd start to see double,
link |
and then next thing you know, I was just covering the eye up.
link |
It was getting weaker and weaker,
link |
just like the atrophy of a muscle.
link |
So I went to the doctor.
link |
They did the exact wrong thing.
link |
The optometrist I went to gave me a prism,
link |
which adjusted it so that I could see things normally,
link |
which just made the eye weaker and weaker.
link |
It's like putting a weak arm into a sling.
link |
So I had to spend at least three years of 10 minutes a day,
link |
is what I recommend, doing near-far,
link |
covering up my good eye, doing near-far with my bad eye,
link |
and now it's been about 10, 12 years
link |
that I have pretty decent binocular vision.
link |
Now, many of you aren't dealing with this
link |
or have these early childhood issues.
link |
Some of you might be experiencing challenges
link |
with fatigued eyes or with differences
link |
in focus with the two eyes.
link |
These eye exercises of near-far smooth pursuit
link |
and checking for dominant and non-dominant eye
link |
can be very beneficial.
link |
Again, I'm not a clinician,
link |
so I don't want to give you protocols or enforce protocols
link |
You need to figure out what's right and safe for you,
link |
given your vision history.
link |
I do recommend talking to a really good ophthalmologist
link |
if you have severe vision problems of any kind,
link |
or if you want to offset vision problems of any kind.
link |
An optometrist as well,
link |
but ideally it would be a neuro-ophthalmologist.
link |
Okay, I did mention hallucinations,
link |
and they're fun to talk about and think about.
link |
For years, people have asked,
link |
why do people get visual hallucinations?
link |
Costello's in sleep right now.
link |
You can probably hear him snoring, he's snoring so loud.
link |
He's probably having hallucinations about rabbits, pizza,
link |
and those are mainly his favorite, and sleep.
link |
He's dreaming about sleep in sleep.
link |
Hallucinations are a property of the visual system,
link |
and it was always thought that hallucinations arise
link |
because of over-activation or activation
link |
of certain aspects of the visual system.
link |
I just briefly want to mention a paper
link |
that was published by my good friend
link |
and phenomenal scientist and physicist for that matter,
link |
Chris Neal, who's up at the University of Oregon in Eugene,
link |
they studied LSD-like compounds
link |
and discovered that hallucinations actually occur
link |
because portions of your brain become underactive.
link |
The visual portions of your brain are understimulated.
link |
This is probably why when people go into these cave retreats,
link |
something I've never done, I don't think I ever will do,
link |
where it's completely black,
link |
pretty soon they start hallucinating.
link |
They start seeing things, even though there's nothing there.
link |
The visual system is desperate to make guesses
link |
about what's out in the world.
link |
It's like the eager beaver of your brain.
link |
It's like, what's out there, what's out there,
link |
Even in low to no vision people, blind people,
link |
their brain is going to be making guesses
link |
about what's out there in the auditory world,
link |
what sounds are there, what touch sensations are there.
link |
For sighted folks, it's going to be
link |
what's out there in terms of light.
link |
Light is the dominant way, vision is the dominant way
link |
that we evaluate the world around us.
link |
So it turns out that hallucinations
link |
are an underactivation of the visual system
link |
and then a compensatory, a compensation
link |
by which the visual system creates activity
link |
and hallucinations.
link |
So if you're in the dark long enough,
link |
you start to hallucinate and see things.
link |
So that's a little note about hallucinations.
link |
One of the things that you can do to improve your vision,
link |
and it's also kind of fun,
link |
is to put a Snellen chart in your home.
link |
A Snellen chart is that list of letters.
link |
If you go to the dreaded Department of Motor Vehicles,
link |
actually, I'm up for renewal soon,
link |
so I love the Department of Motor Vehicles.
link |
The Department of Motor Vehicles
link |
will have you cover up an eye,
link |
read the letters on the chart.
link |
The letters, of course, get smaller and smaller.
link |
They're trying to figure out roughly what your vision is.
link |
Cover up the other eye, you'll do that.
link |
Some people, including nerdy vision scientists like me,
link |
have had Snellen charts in their office
link |
or in their home for many years now,
link |
and you can just practice,
link |
and you can see how you're doing
link |
sitting at a particular distance.
link |
This is something that's not often mentioned,
link |
but your performance on the Snellen chart will vary
link |
depending on time of day,
link |
because your level of fatigue
link |
and your ability to control that accommodation
link |
and other mechanisms of the eye muscles will vary.
link |
So you can take it as an average.
link |
It's also a good thing
link |
if you're going to get your vision tested
link |
for corrective lenses,
link |
or maybe you're going to do laser surgery
link |
or something of that sort.
link |
If you're thinking about any of that,
link |
to really get it measured by a professional,
link |
the ones that you get in those supermarkets
link |
or in many eyeglass stores,
link |
apologies to the eyeglass stores,
link |
are often wrong by an order of magnitude.
link |
And then when you start putting corrective lenses on
link |
that are over-correcting or under-correcting,
link |
but more often are over-correcting,
link |
then you're essentially weakening the system.
link |
It's like putting a prosthetic on a limb that you didn't
link |
necessarily need or a robot arm
link |
when you didn't need the use of the robot arm.
link |
Although now there's so much excitement about robots,
link |
I think people are going to be doing that.
link |
Anyway, nonetheless,
link |
get your vision tested by somebody
link |
who really understands vision,
link |
like an ophthalmologist or a really good optometrist.
link |
If you put a Snellen chart in your home,
link |
you can do that as part of your visual training.
link |
Now, this might seem excessively nerdy,
link |
but what is more important than your eyesight, right?
link |
Eyesight is so vital.
link |
It's right up there with movement
link |
and our ability to move, to generate,
link |
to get up out of chairs and to walk and to run
link |
and to take care of ourselves.
link |
Eyesight and movement are the main ways
link |
that we are able to take care of ourselves
link |
and take care of others.
link |
When you start having compromised eyesight
link |
or compromised movement,
link |
people need to take care of us
link |
and we become much more challenged
link |
in moving through our daily life.
link |
So while it might seem nerdy to have a Snellen chart
link |
in your home or to do a smooth pursuit exercise
link |
a couple of times a week
link |
or to get outside for a few hours a day
link |
and do your reading or your laptop work there,
link |
preserving your eyesight and preserving your vision
link |
is one of the most life enhancing
link |
or quality of life enhancing things that you can do.
link |
And if you're a young person
link |
and you can build some of this into your framework
link |
of exercise or brain training, if you want to call it that,
link |
that can be immensely beneficial
link |
and will really set you up to have really good vision
link |
over a long period of time.
link |
Now, of course there are genetic factors
link |
and there are injury related factors
link |
that can compromise eyesight and our ability to see.
link |
And of course, the things I'm talking about today
link |
aren't going to solve all those issues
link |
but they can have a tremendous positive impact
link |
if you're willing to do just a little bit of work
link |
and none of this is involving any cost, right?
link |
It's just time cost.
link |
So I do want to talk about a few other things
link |
that can perhaps improve vision.
link |
I want to dispel a few myths about stuff to take
link |
to improve vision.
link |
And then I want to just close
link |
by talking about how we perceive time using our vision
link |
because that will nicely set the stage
link |
for what we're going to talk about next episode.
link |
So now you understand a lot about the biology of vision.
link |
You understand that light has to arrive at the retina
link |
and get converted into electrical signals.
link |
That process requires things like vitamin A,
link |
a fat soluble vitamin.
link |
It requires things like the carotenoids.
link |
That metabolic cascade, the biochemical cascade
link |
is essential for vision.
link |
And this is why you've been told
link |
that carrots help you see better
link |
because they're high in vitamin A.
link |
There are a few simple things you can do
link |
to support your vision.
link |
First of all, it is true that eating vegetables,
link |
the dark leafy vegetables and things like carrots
link |
that have vitamin A in abundance
link |
and eating them in close to their raw form.
link |
So naturally occurring foods that contain a lot of vitamin A
link |
in their raw form can help support vision.
link |
Now, does that mean that
link |
if you ingest super physiological amounts of that stuff
link |
that it's going to make your vision that much better?
link |
No, but you do need a threshold level of vitamin A
link |
in order to see and in order to see well.
link |
Now, there's a lot of excitement nowadays
link |
about supplementation to help support
link |
the health of the visual system.
link |
And I'm somebody who's pretty open
link |
to novel forms of supplementation.
link |
You've probably gathered that
link |
if you've been listening to this podcast for a while.
link |
You have to determine what's safe and economical
link |
and right for you, what your risk tolerance is, et cetera.
link |
But I want to talk about a molecule
link |
that's in a lot of supplements to support vision.
link |
And there are some really good data on and that's lutein.
link |
Now, the study I want to describe
link |
is actually published in 2016.
link |
It's from the Journal of Ophthalmology.
link |
It's a good journal.
link |
And the title of this paper might catch your attention.
link |
It's increased macular pigment optical density.
link |
That just means that the macula is an area of the eye
link |
for central vision, for high acuity vision.
link |
Pigment density there is good.
link |
You want pigment there.
link |
Increased macular pigment optical density.
link |
And visual acuity, visual acuity
link |
is your ability to see things in fine detail.
link |
Following consumption of a buttermilk drink
link |
containing lutein enriched egg yolks.
link |
Remember raw foods, lutein enriched egg yolks.
link |
Sounds like a Rocky movie
link |
where he would drink the raw egg yolks.
link |
A randomized double blind placebo controlled trial.
link |
Now I'm not suggesting you go out and eat raw egg yolks.
link |
There's the risk of salmonella.
link |
Although I did hear this, someone correct me if I'm wrong,
link |
but the salmonella is actually on the outside of the egg,
link |
not actually in the egg itself.
link |
It's on the shell for reasons that relate
link |
to how that egg got into the world.
link |
That's where the salmonella lives.
link |
But I could be wrong about that.
link |
But raw egg yolks are not something
link |
that most people want to consume.
link |
What is this lutein stuff?
link |
Well, lutein is in the pathway that relates to vitamin A
link |
and the formation of the opsin, the photopigment
link |
that captures light in the back of your eye,
link |
literally absorbs light pigment in your eye
link |
and converts that into electrical signals
link |
and allows you to see.
link |
And there is some evidence.
link |
I spoke to our chair of ophthalmology.
link |
There is some evidence through quality peer reviewed studies
link |
that supplementing with lutein can help offset
link |
some of the detrimental effects
link |
of age-related macular degeneration.
link |
But, I want to emphasize but or emphasize however,
link |
only for individuals with moderate
link |
to severe macular degeneration.
link |
For people that have normal vision
link |
or with just a low degree of macular degeneration,
link |
these studies did not see a significant improvement
link |
of vision from supplementing with lutein.
link |
So I'm not going to tell you
link |
to supplement with lutein or not.
link |
I don't think any study is holy,
link |
but it does seem that if you have moderate
link |
to severe macular degeneration,
link |
talk to your physician of course,
link |
talk to your ophthalmologist.
link |
I'll always say that and I'll say it three times.
link |
Supplementing with lutein could perhaps support vision
link |
and offset some vision loss in that case.
link |
Probably also talk to your ophthalmologist
link |
or consider the red light therapy
link |
that I talked about earlier.
link |
Whereas if you have normal vision
link |
or a low amount of macular degeneration,
link |
it does not seem at least from these studies
link |
that lutein can have much of an effect.
link |
Now I know and I confess I'm sort of of the mind
link |
that if I personally had age-related macular degeneration
link |
or a propensity for it in my family,
link |
which fortunately I don't,
link |
but in that case, I would think that supplementing
link |
with lutein provided it's safe could perhaps be of benefit
link |
and you might want to consider a low dose of that.
link |
So again, I'm not pushing any of this on anybody
link |
by any means, but you should know
link |
that under certain conditions
link |
of severe macular degeneration
link |
or moderate macular degeneration,
link |
it does seem like lutein can be beneficial.
link |
It does not have to be consumed through raw egg yolks,
link |
although that is the highest density source.
link |
Cooking your eggs, if you like your scrambled eggs dry
link |
or you like your eggs not easy over or whatever, not runny,
link |
then you aren't going to get the benefits of the leucine.
link |
There are other sources of leucine,
link |
non-animal sources of leucine as well.
link |
You can look those up on the internet.
link |
Now, there are other compounds that have been shown
link |
to perhaps be important for offsetting
link |
or helping different forms of vision loss.
link |
One is, I'm going to spell this out,
link |
I-D-E-B-E-N-O-N-E, indebene, indebenone, indebenone.
link |
I can never pronounce these compounds.
link |
Forgive me, unless I've worked with them.
link |
There is evidence that it can be beneficial
link |
for Lieber's congenital eye disease.
link |
I would definitely go onto examine.com,
link |
put in I-D-E-B-E-N-O-N-E,
link |
and for things like Lieber's optic neuropathies,
link |
which is a degenerative condition of the eye.
link |
Whether or not people should just be taking this stuff anyway
link |
is still an open question.
link |
There aren't a lot of studies about it.
link |
A lot of people that are interested in taking things
link |
to support their vision are taking leucine
link |
as a preventative measure.
link |
I don't pass any judgment one way or the other.
link |
Typically, those supplements also include
link |
the zeaxathins and the astaxyns.
link |
Okay, the pronunciation of this is terrible, I'm sure,
link |
but that's not too far off,
link |
but basically, Z-E-A-X-A-N-T-H-I-N.
link |
Let's see what I start to pronounce.
link |
Z-E-A-X-A-N-T-H-I-N.
link |
And the other one is A-S-T-A-X-A-N-T-H-I-N.
link |
Both of these have been shown, excuse me,
link |
both of these have been shown to offset
link |
some of the disruption in vision that occurs with aging.
link |
What is astaxaxin?
link |
It's a really interesting compound.
link |
It's the red pink pigment found in various seafoods.
link |
So shrimp, I'm not a big seafood fan,
link |
but like certain fish, like you'll see at the fish market,
link |
will have that red pink pigment,
link |
and it's also in the feathers of flamingos.
link |
Please don't eat the feathers of flamingos,
link |
and please also don't eat flamingos.
link |
It's structurally similar to beta carotene,
link |
so it's very pro vitamin A,
link |
but it has some chemical differences
link |
which may make it safer than vitamin A.
link |
Remember, vitamin A is a lipid-soluble vitamin,
link |
so it can be stored in our body for long periods of time.
link |
What is the deal with this astaxaxin?
link |
What are its drawbacks?
link |
Well, we can go to our ever favorite, examine.com.
link |
Well, it has a number of different effects,
link |
a huge number, in fact,
link |
but it does seem to notably increase,
link |
it's now been shown in three studies,
link |
the antioxidant enzyme profile.
link |
It has a number of different effects,
link |
but the most notable for sake of this episode
link |
is the one on ocular blood flow.
link |
It does seem to increase the amount of ocular blood flow,
link |
so the blood supply to the eyes,
link |
so that makes it an interesting compound.
link |
There's a number of other effects.
link |
For whatever reason, it also has a notable effect,
link |
several studies have shown this, on fertility in males,
link |
so it seems to at least double the pregnancy rate
link |
when men take astaxanthin and works as,
link |
in particular, it seems here,
link |
in men that were previously infertile,
link |
so I don't know if that has something to do
link |
with the blood flow to the eyes, probably not.
link |
It probably has something to do
link |
with something unrelated to the eyes.
link |
Nonetheless, that's an effect of this molecule.
link |
It's also been shown to have positive effects
link |
on things like skin elasticity, skin moisture,
link |
skin quality, et cetera,
link |
probably due to its effects on blood flow.
link |
So lutein, astaxanthin, A-S-T-A-X-A-N-T-H-I-N,
link |
and for people who have concerns
link |
about Leber's optic neuropathies,
link |
which is going to be a small percentage of people out there,
link |
but that is a pretty severe condition,
link |
there are supplements that are available out there.
link |
I do encourage you, as always,
link |
to talk to your ophthalmologist and physician about them.
link |
And I will say that there are a number of people
link |
that take lutein and some of these other things
link |
as a precautionary measure in order to bolster their health
link |
in the same way that some people take vitamins and minerals
link |
to bolster their health,
link |
and some people are very, health, excuse me,
link |
and some people are very averse
link |
to taking vitamins and minerals
link |
because they feel like they can get all that
link |
from healthy whole foods.
link |
And of course, you can get these things from whole foods.
link |
The question is whether or not
link |
you can get them in concentrations that are sufficient.
link |
I do think that in the years to come,
link |
we are going to see more about lutein.
link |
I think we are going to see
link |
more about some of these other compounds,
link |
like astaxanthin, and hopefully by then
link |
I'll be able to pronounce it.
link |
But at present, these things are more or less
link |
in the kind of experimental or self-experimental phase.
link |
There are some good double-blind placebo-controlled studies
link |
like the egg yolk buttermilk study of all things,
link |
published in really good journals.
link |
Journal of Ophthalmology,
link |
Journal of Investigative Ophthalmology and Vision Sciences,
link |
these are good journals.
link |
These are journals that are peer-reviewed by experts.
link |
The study that I mentioned earlier about keeping rooms dark,
link |
that was also published in an excellent journal.
link |
I think it was JAMA, I'll go back and look.
link |
It's not on my screen any longer, but very easy to find,
link |
and there've been some follow-up studies as well
link |
from the University of Pennsylvania and other universities.
link |
So everything I've talked about today
link |
relates to studies that were done
link |
and published in quality peer-reviewed journals.
link |
That doesn't necessarily mean you want to run out
link |
and start taking the stuff that I've described,
link |
or even doing the protocols I've described.
link |
I've given you an array, a palette, a buffet, if you will,
link |
of things that you could do to try and enhance
link |
or support your vision, depending on how good your vision is
link |
your family history of vision and vision loss,
link |
your occupational hazards,
link |
people that work with metal filings
link |
that are flying out of machines
link |
are going to have a higher degree of risk
link |
to their visual system
link |
than will people who just do office work.
link |
Although if you're doing a lot of office work,
link |
chances are you're not getting a lot of long view vision,
link |
your accommodation mechanisms
link |
are going to start to suffer over time.
link |
I think we can reliably predict that.
link |
So I've tried to give you an array of behavioral tools,
link |
and we did touch upon some supplementation tools.
link |
I'd be remiss if I didn't say that
link |
because blood flow is so critical
link |
for the neurons of the eye.
link |
Remember, these are the most metabolically active cells
link |
in your entire body, the cells within your retina,
link |
because blood flow is required to get them
link |
the energy and nutrients they need.
link |
Having a healthy cardiovascular system, right?
link |
Doing endurance work, doing strength training work regularly
link |
is going to support your eyes and your brain
link |
It's indirect, but it's essential, right?
link |
It's necessary, but it's not going to be sufficient.
link |
You're going to have to do other things
link |
to support your eyesight as well.
link |
But having a healthy cardiovascular system
link |
because it's going to deliver blood and oxygen
link |
and nutrients to this incredible apparati
link |
on the front of your face, these two pieces of brain,
link |
is going to support your overall brain health
link |
and vision over time.
link |
So early in the podcast, I talked about
link |
how the optimal window for learning is 90 minutes.
link |
That's the so-called ultradian cycle for learning.
link |
That's why we held our episodes to about 90 minutes.
link |
They're now starting to extend into the hour and 50 minute
link |
and two hour mark.
link |
That simply reflects my enthusiasm and excitement
link |
about these topics and my desire to give you
link |
as much information as I possibly can in each episode.
link |
Please remember, you don't have to listen
link |
to the whole episode all at once.
link |
Everything is timestamped.
link |
Everything is captioned in English and Spanish.
link |
The captions take a few days on YouTube.
link |
We apologize for that,
link |
but in order to have them done correctly,
link |
it takes a few days after it's posted.
link |
So if you need those captions,
link |
please check back maybe 24 or 48 hours
link |
after the episodes are released.
link |
If you're enjoying this podcast and the information,
link |
if you're finding it beneficial,
link |
there are a couple of things that you can do
link |
that are totally zero cost that really help us
link |
and help you get this information going forward.
link |
One is if you don't already subscribe on YouTube,
link |
please do subscribe.
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We release episodes every Monday and hopefully soon,
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more often than that, shorter episodes as well.
link |
But every Monday we release an episode,
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please do subscribe.
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If you don't already subscribe on Apple and Spotify,
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that's very beneficial, please do that.
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That helps us as well.
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If you could give us a five star review on Apple,
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If you have suggestions about episodes,
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please put it in the comment section on YouTube.
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Routinely throughout the week
link |
after the release of each episode,
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I cover content in shorter format
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and in more depth on Instagram at Huberman Lab.
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Every episode is also indexed and searchable
link |
in the search function on our website, HubermanLab.com.
link |
That's also where we post links to various studies
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And as I mentioned, you can search for different topics
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If you'd like to support us on Patreon,
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There you can support us at any level that you like.
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As well, if you'd like to support us,
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please check out our sponsors.
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The sponsors that we discussed
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We only work with sponsors
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that really does help us.
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Routinely throughout the podcast,
link |
we talk about supplements.
link |
There are a lot of supplement companies
link |
and sources of supplements out there.
link |
The one that we work with and that we partnered with
link |
is Thorne, T-H-O-R-N-E,
link |
because Thorne has the highest levels of stringency
link |
in terms of what they say is in their supplements
link |
is actually in their supplements
link |
because it's independently tested and verified,
link |
as well as the amounts that they list on the bottles
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actually are matched by what's in the capsules and tablets.
link |
That's a serious problem in the supplement industry.
link |
And Thorne deals with that problem by being very truthful
link |
and very accurate about what's in their supplements
link |
and how much of those things are in there.
link |
If you want to see the supplements that I take,
link |
you can go to Thorne, thorne.com,
link |
slash the letter U, slash Huberman.
link |
There you'll see all the supplements that I take.
link |
You can get 20% off any of those supplements,
link |
as well as 20% off any of the other supplements
link |
that Thorne happens to make
link |
if you happen to navigate into their website
link |
through that portal, thorne.com,
link |
slash the letter U, slash Huberman.
link |
And last but not least,
link |
I want to thank you for your time and attention today,
link |
your willingness to learn about vision
link |
in the visual system and the various things that you can do
link |
to help support the health
link |
and functioning of your visual system.
link |
And of course, I want to thank you
link |
for your interest in science.
link |
I'll see you in the next one.