 Well, everybody, I just want to thank you for all coming to my talk. We have a smaller group, so we'll be pretty intimate here as we get into this. A quick question before we get started. How many of you guys are actually near-sighted? Raise your hand. OK, so a fair amount. I guess it's kind of self-selective if you're far-sighted. And I've never had this problem. You're probably like, I don't care what this guy has to say. Which is fair enough, because I wouldn't either. So before we get started, I just want to let you guys know that it's going to be kind of rapid fire. We have a lot to go through. And if you just bear with me at the end, we're going to come to some conclusions that are groundbreaking and will change all of your lives. But you already know all the answers to those groundbreaking things. So when we get there, you'll have figured it out. So first thing we're going to do is kind of go through a quick anatomy lesson with the eye, OK? So the bigger circle here, that's your sclera. And what sits on the sclera there is your retina. So the retina is the photosensitive tissue that lets the light information get back to the brain. This is your crystalline lens. That's what we use to focus. And we'll kind of talk about that a little bit later. The front part here, that's your cornea. That's the clear part, but the light travels through in order to get to the back of the eye. And the white lines here are just depicting light, specifically parallel light rays. Parallel light rays are anything that comes from an object that's more than 20 feet away. So what we would call optical infinity. And so this is just an example of what we would call an ematropic eye. Or someone that is perfectly sighted can see in the distance and up close. So here we see that the light rays are bent. When they hit the cornea, they bend a little bit more. When they hit the lens, and then they're focused on the retina, and your brain perceives a clear image. So what happens with myopia or near-sightedness is we get this eye growth. The refractive properties of the eye actually doesn't change at all. It's just that the eye grows backwards through a few signals. And we'll talk about that here in a second. So with that eye growth, what happens is the rays of light are still bent and focused in front of the retina. And then they continue to diverge. And that's what our eye perceives as blur when we're looking at distant objects portrayed by the parallel light rays here. So traditionally what we do is we give a person a concave lens here. And what that does to the parallel light is it diverges it. So this could be in the form of a spectacle or a contact lens. They serve the same purpose. And what it does is it diverges the light, bends it outwards. And then the cornea and the lens bend it back in. And then it's focused on the back of the eye. And you get a clear image. So near-sighted folks wear glasses so that they can see in the distance. Most of them can take them off, see up close. So let's talk about, is it even a big deal? Why are we talking about it? And what we can see is, as far as the prevalence, it's increased exponentially in the last 100 years. In 1925, there was a survey of German schoolchildren. About 16% were found to be myopic. Then we had a huge study in the United States that looked at the whole United States population. In 1971, it was about 25%. And by 2004, it had increased at 41%. And there's a group in Australia that is really big into this stuff. And they're predicting that by 2050, one in two people will be near-sighted. So just like everything else we've talked about at this meeting, is it nature or is it nurture? And I think you guys have a leg up on most of the folks as far as knowing that it's a little bit of both. But nurture or environment plays a huge role. So one of the theories, people, near-sighted people, they can't see far away. So that means they have to get really close to each other. They start to like the other person. And is it just that myopic people spend more time close up and they have more myopic babies? Probably not. But what we do find is that there are a few phenotypes that can predict a little bit of your risk for myopia. So if you have one myopic parent here, one and a half times more likely to become myopic. And if you have two myopic parents here, two times is likely. But at the end of the day, I think we, at this point in time, can say that the phenotypical variation influences the susceptibility to myoptic factors in the environment. So I'm myopic. My wife is myopic. Are we destined to have myopic children? Not necessarily. There's things that we can do to hopefully prevent that. So just like everything else we talk about at this meeting, we look at our evolution and our ancestry to kind of give us some answers to what's going on. And what we find is in native populations, hunter-gatherer populations eating traditional diets and living a traditional lifestyle, the prevalence of myopia is under 5%. It's almost unseen in those populations. And these were both done in about the 1950s. This was in Equatorial Africa, Greenland, some Inuit or Eskimo populations. And then these rural Tibetan school children. So it's not just one area of the planet that's experiencing these low rates of myopia. It's kind of spread out all over the place. But that begs the question, what is it about the hunter-gatherer and traditional lifestyle that is protective against myopia? And that's where we kind of have to start digging into the details and figure that out. So a study done in Barrow, Alaska looked at one population. So they took everybody and split them into two groups. Everybody over 40 had mostly been unexposed to Western influences throughout their lives. So they lived a traditional diet, a lot of seal and whale blubber and deer salmon, stuff like that. Maybe the original ketogenic diet. And the younger group, less than 40, had been part of the US government's attempt to kind of Westernize and modernize the Native Americans. And so they were introduced to industrialized foods and also to modern schooling. And we find that the difference in the rates of myopia are pretty incredible, 1.5% to almost half of them being myopic. But then you still have two things on the table. Is it what they're eating or is it just that they're looking up close at their books all day long? Well, we look at another study here done on a population of school children and on a South Pacific island. And what we see here is that they were engaged in modern schooling, their definition. They didn't give a great definition in this paper of what that meant, how much time they spent looking up close or doing those things. But they were still eating their traditional diet that their ancestors had eaten for a long time. And they were still kind of in that single digit, less than 5% range. So does that make a clear statement that it is diet alone? We don't know, but we have some pretty convincing evidence that it could be a factor. So a mechanism proposed by a little-known guy back in the early 2000 named Lauren Courdain on this issue was that with increased consumption of carbs and refined sugars, you get an increased insulin resistance. And yeah, so they're not the only ones talking about insulin resistance here. With that, you get a compensatory hyperinsulinemia. And that decreases hepatic insulin-like growth factor binding protein. You get higher circulating insulin-like growth factor, and that increases eye growth. And what we've seen in the chick model, since this has been proposed, is that when you intraocularly inject growth or insulin-like growth factor and insulin, it increases axial length, which goes back to what we were talking about, that eye growing longer. And when you inject glucagon, basically the opposite of insulin, you get either stability or even the eye actually shrinks a little bit. So could it be diet? Absolutely. But it's very difficult for us to take a population of school children who, at least in the United States, who are not eating a Westernized diet and follow them for the amount of years that it takes to develop myopia. Myopia typically develops about eight or nine years, but it cannot stop until about the early 20s. So those studies just haven't been done yet. But another factor of our environment that's very mismatched, that's kind of a buzzword here at this conference, is light levels. So what we see here is that sunlight compared to other artificial lighting, like what we've got in here is both full spectrum and very high in intensity, where these other sources of artificial light have spikes and are relatively low in intensity. So there was a study done in Australia about two years ago where they took a bunch of school children and for about 18 months they wore these wristbands and Dan Perry kind of talked about it yesterday. They track both movement and the amount of light level that the kids are getting. And what they found was that those who are exposed to over 650 lux on average per day progressed much slower in their myopia than those who had less than the 651 lux. And that equates to about 40 minutes or so outside. Now just to be safe, I would say that 60 minutes is probably a better number, but that's what they found in the study. And because they were able to track the children's activity as well, they found that there was no correlation between the amount of activity that they did and the amount of myopia that they developed. And that's been a point that's been kind of argued for a long time. What is protective about being outside? Is it light or is it just the fact that they're outside playing, moving around, doing those things? So this pretty definitively says that it's the intensity of light and there are a few theories out there that it could also be the spectral makeup of the light. So blue light actually being protective at the correct times during the day. So I know all of you guys are wearing your orange tinted blue blockers at night. Keep doing that, that's great. But don't wear them during the day. We wanna make sure we're getting that good blue light during the day. But still protect yourself from UV, wear your sunglasses. So what is the mechanism behind the light? And one of the proposed mechanisms is that as light intensity increases, it's correlated well with this increase in intraretinal dopamine. And eye growth is not a kind of linear progression. It's a diuronal curve. And the diuronal curve actually correlates almost perfectly with these rises and falls of the intraretinal dopamine. So we think that that's pretty intimately tied. And we see with folks with lower degrees of myopia or no myopia at all tend to have much more intraretinal dopamine during that diuronal curve and those who don't have spikes at times when we typically would not see a spike in that intraretinal dopamine. So getting the right amount of light and getting it at the right time is super important. Another proposed mechanism for why light works is that the ultraviolet light exposure on our skin raises our vitamin D production. And the one correlative study found that kids who are myopic tend to have lower circulating vitamin D levels than those who were not myopic. And so correlation causation, we still haven't figured out if there's a mechanism that can explain why vitamin D might play a part. But everybody here knows that vitamin D does so much and it's more of a hormone than a vitamin. So we'll see kind of where the research goes on that. So switching gears from kind of this environmental stuff, you know, what we typically talk about here in light and diet and outdoor exercise, we're gonna get back to the elephant in the room, which I think a lot of you are aware of in that most people have thought throughout their whole lives that they're not doing near work, that the continual looking at near objects, especially under insufficient light is the cause of myopia. And is that really true? That's, you know, don't sit too close to the TV, your eyes are gonna get messed up, don't read all those books, you're not gonna be able to see anymore, you know. We've heard that since at least for a hundred years. So is there any credence to those recommendations? Before we get into, before we find out the answer, we'll talk a little bit about what it takes in order to see things up close if you're not nearsighted. So here we have the eye again and instead of having light coming straight into the eye parallel, we're having the white diverge and this is what happens when you're looking at any object that is closer than 20 feet, okay. So this is looking at a near object. So what happens is the light comes in, it bends but not enough and it's deep, and it focuses behind the retina and the eye interprets that as blur. So what happens, the lens inside your eye becomes wider and has a smaller radius of curvature, bends the light more and that's what allows you to see images clearly up close if you're not already myopic, okay. And most children are not myopic. Most children between the ages of one and five, the rates of myopia are in the single digits. So people are not being born myopic. So for a child, this is how they see things up close is through this mechanism and this mechanism is driven by the parasympathetic system in our bodies. And so both you get pupil constriction and this bending of the crystalline lens. So is it the near work? Is it this continual bending of the crystalline lens that's causing the myopia? And it's been really mixed results for a very long time. Once they'll come out and say, yep, near work, you can predict if someone's gonna become myopic by how much time they spend looking up close. Another study comes out says, nope, there's no correlation. And what I've come to realize is that it's kind of like if we were to say, two people went to the gym three times a week for 60 minutes and at the end of 12 weeks we said, this person lost 50 pounds and this person gained a pound. But that's all we know. That's kind of what we're talking about when we say near work. No one really explains what near work is or how intense it is for someone to do that. You guys might realize that it's not just the clarity of the image up close. You have this coordination of your eyes in the eye muscles and also the focusing system that needs to be done in order to maintain a clear single image up close. And that takes a lot of cognitive energy. And for most people who don't have any issues with their eye movements or eye teeming abilities, it's relatively low in their, they need to put forth a relatively low cognitive effort in order to maintain that. But for some people, it's extremely high and especially for a child who has not learned how to use their eyes yet, it's extremely high. So someone reading the same exact book at the same age, one might be using 90% of their capacity and the other person might be using 10% of their cognitive capacity to get in that information, that visual information. And I think that's what explains kind of these mixed results that we're getting. No one's ever corrected for how much cognitive energy that subjects have to put forth in order to do this near work. So the proposed mechanism on why near work would cause myopia is that what you get is when you have a stimulus up close, you get an initial sympathetic response that is then followed very abruptly by a parasympathetic response. And what we talk about a lot in here is this kind of imbalance of the sympathetic system, that it's the cortisol and everything like that, that causes issues. But it's the same thing can happen with the parasympathetic system. They're in a balance for a reason. So if you have the parasympathetic system having this chronic innervation of the ocular tissues, that's where you're gonna have a problem. You're going to get out of homeostasis with that chronic parasympathetic response. And what you get is you get that autonomic imbalance and then the eye's saying, I'm doing all of this work. The brain's saying I'm doing all of this work. Why do I have to put forth so much effort to keep things clear? Wouldn't it be easier for me to just grow? And then I don't even have to use the focusing system anymore. Everything's naturally up close to me because the eye is longer, okay? And so that I think is kind of a signal to the eye to continue to grow, but we haven't figured out what the mechanism is yet. Behind that, the one thing that might provide some evidence that that could be it is that we use atropine, which is a parasympathetic blocker. And what it does is a lot of folks use that to actually slow myopia. So by blocking the parasympathetic system, we think that that can actually slow myopia progression. And then the last thing, that's kind of the darling of the opometric world is what we call retinal defocus. This is optometry's holy grail of myopia right here. So I figured I'd include it. So here we have our eye, our endotropic eye, not nearsighted. This is a perfectly sighted person, parallel light coming in and focusing on the back of the retina. But as we know, light doesn't travel in nice little straight lines at the very center of our eye. We also get these kind of peripheral light rays coming in, going through our eye and focusing sometimes in front and sometimes behind our eye, even though the image on the center of our macula, that's your central vision, looks clear to us. So in the periphery, your vision is about 2100. So even if an image was blurred, you wouldn't really be able to interpret that blur very well. So we think we're corrected perfectly, but you're getting these blurred images presented to what we call the peripheral retina. So what happens? The eye grows out to focus that image on the peripheral retina. And if there's enough blurred image on the periphery of your retina and it makes a robust enough signal, then the eye grows backwards. So what happens when someone becomes myopic? We put a spectacle lens in front of them. What we get here is what we call an image shell, okay? And so while the light rays that come through here, come through the center, are perfectly focused on the back of the eye, the images from those peripheral rays that we looked at earlier are actually focused behind the eye. And so it goes back to what we were talking about earlier. If you have enough of an image focused behind the eye, the eye has incentive to grow to, in order to get those images clear, okay? And so this is what we see. The spectacle lens, creating that image shell, we get continued eye growth in order to focus those peripheral images on the back of the eye. Now, you could say, well, why don't we just give the child less power than they need, under correct them, so that the light focus is in front of the eye, and shouldn't that work? And there's some mixed results. Depending on how much you actually are under correct the child by, it will either actually make the eye grow faster or slow down in growth. And so not correcting a child is, there's some mixed results on whether that actually works or not. But if this paradigm is what is true, then it should work, but we've seen that in some cases it doesn't. So this basically, in my mind, proves that this can't be the whole story, this retinal defocus, which a lot of people have taken as gospel. And that brings us to our another point. There's a poor correlation with that peripheral refraction. So peripheral refraction is those light rays coming in from the side and focusing behind the eye. We have ways of measuring how much focus, how many light rays are being focused behind the eye or in front of the eye. We have instruments to measure that. So you would think if more light is being focused behind the eye, that should correlate well with the amount of myopia that someone has, because if that retinal defocus theory is true. And what we find is that the peripheral refraction is poorly correlated. Someone who has the light focusing way behind might not become myopic and someone who has the light focusing right on the retina, they might become myopic no matter what you do. And what we do in order to change the peripheral refraction is we do multifocal optics. So we correct that central image right on their macula. We make that fall right on the retina, but we take those side rays and we actually make them focus in front of the retina to hopefully give the eye a signal to stop growing. Because if there's no light being focused behind, there should be no signal for it to grow. And what we see is that works about 50% of the time. It slows the progression, it doesn't stop it. So if this peripheral refraction and retinal defocus were the whole story, it should be 100%, right? We should be able to stop myopic children and myopia shouldn't exist if this was the whole story. And that's what brings me to the understanding today that we're not really there yet. It's still kind of in its infancy as far as our understanding of what makes someone myopic. And I think we have to stop looking at it as a disease and I put that in my title, so I'm at fault here for saying that it's a disease. But I'm looking now more at it as an adaptation or a homeostatic mechanism, thank you. And so if we look at a traditional negative feedback loop, we have a set point here and we have a stressor and then a corrective action to bring you back to your set point and we have obviously time on the x-axis here. So the theoretical model for this is that you have a set point and that's kind of your refractive error or the amount of nearsightedness or the amount of farsightedness that someone has or the perfect hematropic eye that someone might have. And what we get is we see that the stress is, over time the stress is introduced and removed. So let's say you're not getting enough light, low light levels can act as a stressor like we talked about earlier. The increase in carbohydrate act as a stressor with the insulin or you're doing a bunch of near work, you're having this parasympathetic response, that could be a stressor. And then as you move through the world, you go outside, we look at things far away, you eat better food, the stressor removed in it, it goes in a cyclic cycle or maybe not cyclic, maybe you just spend all your time inside eating crappy food and reading and then it's just straight across. But as long as it doesn't cross this threshold, you're okay, you're not gonna have the eye growth. And this threshold is determined by your genetic media. So some people who are exposed to the same things, they might be more susceptible because of their genetics. But let's say the stressors go over that threshold and you spend a lot of time in this zone where you're exceeding kind of that limit that you can take as far as those environmental stressors go. What happens? You reset the set point so that the stressors then fall below the new threshold. And so we go back and look here and what we see is what happens if you lower that threshold? What if your genetic makeup is one that puts you at more risk for these things? What if you have two myopic parents and that the stress for one person didn't do anything, they're fine. But for this person, the stress level, the same stress is over their threshold and they get that new set point and they, so that they're no longer crossing that threshold, they're underneath it. So after all we've talked about, what ends up happening is that you get all of these different thresholds for all of these different environmental factors that we talked about. Light, diet, how much near work someone is doing, how much effort it takes to do that near work, how much light is being focused behind their eye, that retinal defocus. And what we see is while some of those things, some of those thresholds might not be crossed, others could be. So you might be doing everything as a practitioner that you can optically in order to stop this progression but say the person's not getting enough light, they're still going to progress in their myopia. It's not until you correct all of these stressors and get them all underneath the threshold that you're going to get a stoppage of myopia progression. So, like I said at the very beginning, you guys all know the answers to what you need to do in order to stop either the development or help stop the development of myopia or slow its progression. Stop, limit refined carbs and sugars and make sure that your blood sugar levels are where they need to be. Promote play outdoors, get the kids outside, doing activities, making sure that they're getting exposed to natural sunlight. And then just looking in the distance and outside there's very little, when you're outside playing there's very little that holds your attention up close for a very long time unless you're looking at ants with a magnifying glass or something like that. So just getting outside, looking at distant objects, playing and eating a good diet. And then as far as if those things aren't working, there's things that we can do as practitioners that can help to slow that to correct that peripheral defocus, that retinal defocus in what we use are multifocal soft contact lenses, ortho keratology and some practitioners also use that parasympathetic or that parasympathetic block or atropine to slow the progression of myopia. So that's basically it in a nutshell guys. These are all my references. Here's my contact info if you guys have any questions about anything. These are a few blogs that I write for if you're interested in learning more about the topics that we talked about today. And I just wanna say that I really appreciate you guys being here and listening to my presentation. Thank you. Yeah. Questions? Great. There's a microphone over there, I'm pretty sure. And if anybody's closer to this side. Hello, okay. I'm concerned about wearing contact lenses and not getting natural light in my eyes during the day. So I'll sometimes go on a hike when I can't see a whole lot of anything just to get light in my eyes. Cause it feels like I'm blocking this natural nutrient that I'm supposed to be getting. And then you see contact lenses coming out with UVB blocking lenses, which sounds really backwards to me. So what is your take on those of us who are wearing contacts and are we cutting off this mega nutrient supply? No, that's perfectly fine. So light in the visible spectrum which contact lenses allow through obviously or else we wouldn't be able to see through them are fine. They are protective in the UV light. So UV light is dangerous and harmful to us causes cataracts, macular degeneration. So you're certainly not doing any harm by wearing your contact lenses. The only harm that you're doing is spending your whole day inside. So if you go outside, you're wearing your contacts or even like I said, sunglasses, the study that with the children and the light levels, all of those children were actually wearing UV protection and so they were still able to get enough light in in order to slow that progression of myopia. So hiking around when you can't see anything in the distance, is that exercising your eye? Is that good for us or is that doesn't do a darn thing? Yeah, it doesn't. So we can slow the progression and the progression will stop, but we can't shrink the eye. We haven't been able to find a way for the eye to shrink. So by not wearing your corrective lenses, you're not, there's really no way that you're actually going to be able to become perfectly sided again. And most of this stuff that I'm talking about here is the progression basically, except for a very few cases, stops by about the age of 20. So when you hit 20, whatever your kind of refractive air is, that's what you're gonna be typically for the rest of your life, but there are a few variations as we go through. Well, thank you. Sure. Todd, hang on just a sec, we'll kick it right back to you. Hi, thanks. That's interesting about short-sightedness, but if I remember my late mother-in-law, the problem was as she got older, long-sightedness until eventually she would have restaurant menus and her arm was no longer long enough to read the menu, do you have any comments about long-sightedness? Yeah, so that's what we, it's very common. And when I say it's very common, it means that 100% of you guys will get that. That's what we call presbyopia, okay? That crystalline lens inside your eye becomes too hard and it can no longer bend in order for you to focus up close. So someone sighted actually can get by by actually using a little bit of that focusing system to see clearly in the distance and then as time goes by, that lens becomes hard, you can no longer use that and that's why people come in with a complaint of their arms are too short. So, unfortunately, they're working on a drop now that actually resolves the elasticity of that lens. So maybe in the next 10 years, presbyopia or that need for reading glasses as we get over the age of 45 or 50, that could be on the horizon of being cured. So great talk. About 20 years ago when I had strong myopia, I started using plus lenses and I also went on a low carb diet and I reversed my myopia and I wrote about it and then I talked about it actually two years ago at Berkeley and I agree with so much of what you said about mechanism, but you really were talking about myopia prevention, not about myopia reversal. And one of the references I saw you flash up by Scott Reed looked at how incremental defocus in chicks can actually make the eye not only grow longer but can make it grow shorter. And when I've put that out there, even based on the research, optometrists don't tend to accept it. So I'm wondering about your view on the possibility of myopia reversal since I've experienced it and hundreds of others have. Sure, and that's a good question. And I think the point with that paper that can be made is that those chicks were in what we call, we're relatively young, kind of like our children. They were in this period of elasticity essentially. And so while you might be able to get a little bit of reversal, there's nothing that we found that is robust that tells us that in the human model that you do decrease the eye growth sort of exercises or anything like that to actually reverse the myopia. That hasn't proven in any of the literature up into this point. Okay, but people do reverse their myopia. So somebody needs to explain it then. Okay, how many examples do you have of people reversing their myopia? Dozens, I mean, I can send that to you. Yeah, that'd be great, I'd love to see that. You may have covered it, you just mentioned the right amount of light at the right time, I'm curious. And then is it dangerous to look directly at the sun? I have friends that do that. Do not do that. Okay, and with the eclipse also. And then I just don't like wearing tinted sunglasses, but people always say I should. So you might have already mentioned that. Yeah, so the tint is, the only thing that the tint's doing is reducing the amount of visible light. I still recommend that you wear UV protection. So a lot of the coatings on a standard prescription lens do have a UV coating. So that if you just want to wear a clear lens, I recommend that you do have that coating that UV blocking coating put on there. I think we have time for one more quick one. Can you talk about, you mentioned the importance of natural light in the morning. We live, well, at least I live in Seattle, there's rain, there's lack of sun. Can you talk about potentially substituting that with a light box in the morning? Yeah, so I've been thinking about that a lot actually. And what you see when you look at, even on a cloudy day, the light levels are exponentially higher outside than the official lighting. So on a sunny day, you get about 120,000 lux of light. And even on a cloudy day, you get about 60,000, 60,000 units of lux. And in your home, it's significantly less than that. Even though it seems right, our eyes are so good at adjusting for the, we'll say the exposure environment, even though you perceive that the light levels in your house are the same as on a cloud, it's worth getting outside because you're still getting an extra of natural light outside. Great, thank you so much, Dr. Turpin.