Seems to make sense to me, hair is just dead skin and skin benefits from access to sunlight… so would stand to reason hair would also degrade faster if it loses access to sunlight.
Pretty interesting. The dominant hypothesis now is that exposure to daylight is the main variable. It explains why myopia seems, like diabetes and heart disease, to be what doctors call a “disease of affluence”—more common in rich countries than poor ones—since economic growth brings with it more education, and therefore, for children, more time inside.
Exposure to very bright light (even standing under a shade tree on a cloudy day is far brighter than normal indoor lighting) specifically during key years had been nailed down with high confidence as the primary cause of most near-sightedness, last time I looked into this.
Not sure if they'd figured out the mechanism, but speculation was that bright light is involved in signaling the eye to stop lengthening at the right time.
IOW the cause is, basically, school. In Winter months, kids may hardly see the Sun at all, with very short days and recess often indoors (too cold, too snowy, too wet) especially as schools have seemed to grow more wary of taking kids out in poor weather, over the last few decades. Plus anything else that keeps kids indoors, sure (video games, social media[0]) but school seems to be a lot of it.
[0] And actually, the social media factor likely kicks in well after it matters. Ditto video games unless your kid becomes a gaming addict in the 3-7 age range and you just let that happen.
Yeah typo. The theory is that eyes change shape over time (I think starting out longsighted) and at some point a hormone is released to stop this changing. It is released when (a) the eyes are typically around the middle of their focal range (ie looking at middle-distance things is done with relaxed eyes) and (b) there is a lot of light. Without the second condition the shape of the eyes will continue to change and then you get myopia.
See also: metabolic bone disease in lizards. Also caused by a lack of light — in their case, near-UV light.
(My understanding is that the thing changing the shape of the eye over time is the development of the orbital socket bones — so nearsightedness and MBD could have more in common than it seems.)
Yeah, typo, too late to edit. Insufficient exposure to bright light during key, early years while the eye is developing was found to increase risk so much that it's practically all that matters, at least over a population (I'm sure some unlucky people get it for other reasons, like most things)
I grew up near the equator where there is a very high rate of myopia despite exposure to sunlight. (Sure we spent a lot of time indoors, but we were exposed to sunlight all year round since there’s only one season: summer).
I think genetics has a larger predictive effect than sunlight.
I’ll grant that with indoor malls and public transit there’s less exposure to direct sunlight, but you still can’t avoid being exposed to the sun daily in Singapore.
The amount of time you spend in sunlight matters. Kids went from running around outdoors all day (whether for work or play) to spending all day sitting in classrooms.
There is/was a very strong aversion to being outdoors, especially during peak sunlight hours (lunchtime). This compounds with both study culture and digital culture (videogames + tv + phones) and less of a celebration of sports to mean many kids get less direct sunlight than you'd think. Especially now everyone is terrified of UV
I don't think OP mentioned being in the direct sunlight, but being exposed to it (visually, as in a source of bright light). Unless you sequester yourself in a room without windows all day, to get anywhere you're likely to need to walk outside to a bus stop, an MRT station, or to get a Grab. And unless there's a tunnel connecting office buildings to hawker centers, folks probably need to walk outside to get lunch (exceptions are malls connected to food courts).
Singaporeans probably get more sunlight than say Swedes over the course of a year.
> Singaporean children had shorter reported time outdoors and
lower light levels, relative to their counterparts overseas. In the
current study, reported time outdoors was 1.7±1.6hours/day
and average light levels were 458±228lux. In contrast, children
of similar ages in Australia and the UK reported time outdoors
of at least 2–3 hours/day.18 22 Likewise, higher average light levels
of 1072 and 1627 lux were reported in Australian (age 10–15
years)16 and American (age 5–10 years) children,20 respectively.
Differences in educational demands (homework load and afterschool enrichment classes),23 lifestyle and sociocultural factors
may account for the lower reported time outdoors and light
levels in Singaporean children
I can't remember exactly how many hours of exposure to sunlight the studies mentioned, but I think it was something like 2-3 hours --- and it might have to be more than just, e.g., being near a window. I'm Singaporean too, and that excerpt from that paper accords with my experience. I highly doubt that I and most of the people I grew up with had that much sunlight exposure per day.
Fair enough - not trying to condescend just establishing what your opinions may be based on.
My own personal (and very anecdotal) observations are that people really go out of their way to avoid exposure to the outdoors. Depending on your lifestyle, it is really possible to spend the day having only been outside for minutes of a day.
I think things are changing but I feel like the last 20-50 years have not really celebrated an outdoors lifestyle. Whereas my time in Europe is somewhat different in that plenty of people optimise to spend time outdoors - probably due to less oppressive weather and kids were encouraged to play outside a lot more
Not buying the sunlight argument, equatorial countries are hardly afflicted by vitamin D deficiencies or seasonal affective disorder you see in Europe. Solar intensity is stronger year round than summer in some Scandinavian countries. If it were sun, we'd see similar patterns in myopia to vit D deficiency as you get closer to the poles.
This is def a decent counterpoint - on a previous HN thread on this topic I recall studies being done on agricultural vs urban mainland chinese people and how a refinement to the observation so sunlight/outdoors might be a proxy for some other factor. I've seen proposed "distant viewing".
Although one possible nuance is that sunlight to the eyes != sunlight to the skin. In cold climates you wear thick clothes which will block out sunlight to the skin (vit D deficiency) but you may still get plenty of UV to the eyes. Throw in some mountains for distant gazing and suddenly nations that love skiing could be simultaneously vit D deficient but guarded against myopia.
Pure conjecture of course - IANA(Biologist/Opthamologist/Doctor)
I don't think historically (at least in the past 40 years) most people (barring construction workers and certain jobs) from that region were ever out for 12 hours a day in the bright sunlight.
You can read a book outside under a tree and get enough lumens. When we switched to backlit screens for showing information, this necessitated that more time be spent indoors to be able to make out the words on the screen.
I'm not sure this is the argument you are trying to make, unless Singapore moved it's position on earth. Not that genetics are any more convincing, seeing how it's only 50y.
Have any studies been done comparing children raised in Portland and Seattle (where it rains for the majority of the year so kids spend a lot of time indoors) versus San Diego or some other sunny city?
Their big breakthrough in understanding myopia occurred in 2008 when they studied a particular group of people who had a genetic form of myopia that’s very severe. They discovered a gene mutation that was causing the myopia.
“It turns out it was a mutation in the cone photoreceptors,” said Jay Neitz. “We then realized that it’s really just the way that the images are being encoded on the retina.”
What’s supposed to happen as your eye grows, is that things should begin to go out of focus in the periphery of your vision. That’s a signal for the eyes to stop growing.
But as long as things are still clear in the periphery, the eyes think this person must still be farsighted, because in the natural world things in the periphery are far away.
Neitz said his team was able to design a lens to make central vision clear and in focus, and give the peripheal vision much lower contrast.
“It recreates what is supposed to be going on with our eyes before we started putting all of these things in front of our face like computer screens and tablets,” he said.
Update Jan. 20, 2021: The North America myopia trial is nearing the end of its second year and it is closed to enrollment. Based on the one-year data, the eyeglasses have regulatory approval to be sold as medical devices in Europe and Canada. They are currently being sold in Canada under the brand name "Kikko." Researchers anticipate regulatory approval in the United States in about a year that will be based on the two-year results. People can go to the Kikko website https://kikkovision.com/ and sign up to receive updates about U.S. availability. Once they are approved in the U.S., people will be able to buy the glasses from their optometrist or ophthalmologist.
„The CYPRESS clinical study3 enrolled, randomized, and dispensed the lenses to 256 eligible children across 14 clinical trial sites in the United States and Canada. At the time of enrollment, subjects were six to 10 years old having myopia between -0.75 D and -4.50 D.
After two years of wear, 85% of children wearing the innovative spectacle lenses showed less than one diopter of myopia progression.4 Moreover, the study also showed that 41% of the children wearing spectacle lenses with Diffusion Optics Technology™ showed no clinically meaningful progression in refractive error after two years versus only 17% in the control group.5“
> The dominant hypothesis now is that exposure to daylight is the main variable.
Which is obviously wrong. The main variable is the time the eye spends at a short focal length. Like every other part of the body, the eye adapts to the stresses it experiences. Focusing on nearby objects for extended periods is stressful for a normal eye and as is the case for so many stressors, the body adapts[1]. This is easily seen in that ceteris paribus a person with myopia can comfortably focus on much closer objects than someone with normal vision.
Incidentally this means that corrective lenses can actually cause myopia to progress. Contrariwise a prescription can be written such that there is an effective training stimulus to reverse myopia[2]. However, that won’t fix the decreased focal range due to age related hardening of the lens of the eye.
[1] See Selye for details.
[2] Inexplicably, most optometrists refuse to do so.
Reminds me of a memoir titled "house of sticks" written by Ly Tran, who experienced blindness from a very young age. When she escalated the issue to her father, asking for glasses, he denounced them: he was convinced that glasses were a conspiracy made by the government to control citizens.
Glasses tend to degrade vision.
What if previously it was impossible to afford glasses , so your eyes never got so bad?
Then again 2 out of 3 Asians I've dated wore glasses. My first girlfriend and mine's frames touched when we kissed.
The 2 were both Americans, so it would point to a generic explanation.
Then again a geneticist friend of mine pointed out the egg that made you was actually created inside of your grandmother. So bad nutrition, due to famine perhaps, can easily affect multiple generations.
Rather depressing to think about how the grandmothers of most people likely suffered though some form of famine. It's really great to see global poverty decrease to such a level this won't be the case in 100 years.
It isn't like your eyes are healing or anything. This isn't what we are doing with glasses because your eyes aren't injured. Using glasses is more akin to using crutches when your leg simply will never work - neurological disorders, permanent disability, and so on. The crutches help you get along. Or maybe you aren't using crutches, but instead a brace for drop foot or some other sort of support.
What you are referring to is something that will heal - an injury. And crutches are good when you are healing, too - those times you do not want to put weight on a leg. In these cases, you don't want to use crutches too long lest you have atrophy or stiffness. But this isn't like glasses at all: In this case, for eyes, you'd use things like a temporary, protective contact and/or an eye patch (There may be cases for glasses, but I'm a layperson and simply cannot think of any right now)
Your eyes aren't static objects and can change the lens shape and your focal distance to an extent. The theory is that by not forcing your eyes to strain and exercise towards seeing things at a farther distance they don't get the very exercises that may mitigate or delay further degradation or change in focal length in the opposite direction.
I don't know of any research offhand that definitely says it does or does not permanently effects your vision, but it isn't hard to get confusing or contradictory results if studies aren't well prepared specifically because your eyes can change focus slightly through concentration and can also get tired and will effect the maximum focal change possible at different times.
Usually people wear crutches for short-time only because they are recovering from some sort of injury. Obviously leg strength degrades because of the lack of exercise, but walking around with a broken leg also leads to a lack of exercise and reduction of leg strength.
That is an error in your brain's perception of things. When you use glasses for a while, your eyes get less used to straining and different muscles in your face relax. Then, when you go without, you notice the strain. This same sort of thing happens when you switch prescriptions as well (not to mention that folks' eyes might degrade as part of normal aging). Realistically, these are the same sort of things that drive folks to the eye doctor because they are having headaches.
There's a popular theory (hormesis I think it's called) that says this. It's also just something that's popular among people that are "just logically thinking" / "using common sense", I've heard it for as long as I've had glasses (decades).
Not a single doctor has agreed with this sentiment and I've never found any significant studies conducted that support this claim. If it were true you would expect it to have a lot more actual backing than it does, especially given how long the theory has been around now.
>Switzer talked about how her husband, who served in Vietnam from 1968-1969, was recently diagnosed with prostate cancer. She also shared that both her son and her granddaughter were born with birth defects. Switzer mentioned higher rates of miscarriage, stillbirth, learning disabilities and asthma among the children of veterans as well. “All you vets out there, we need you to get your medical records and give them to your family. And us — we need to put down on our own medical records that our husband or father was in Vietnam and exposed to Agent Orange,” she said.
Or, maybe integration poverty causes all of your kin to eat poorly
Unlike men who are constantly generating gametes (sperm) women are born with their gametes(eggs) and don't make any more throughout their life. This means that all the eggs of your mother (one of which became you) were created while she was gestating inside your grandmother. Now, how much your grandmother starving influences _your_ eyes is up for some debate, as epigenetics aren't well understood.
But fathers develop inside their grandmothers as well, exposed to everything they are exposed to and undergo epigenetic changes that could influence sperm production.
Interestingly enough, scientists have been able to induce myopia in all sorts of animals by making them wear contacts.
My suspicion is that staring at objects closely and under dimly lit conditions causes pseusdo-myopia which is later exacerbated by wearing glasses, causing actual axial elongation in the eyeballs through hormesis. Especially since this is what seems to happen in other animals when we dissect them.
I'm modulating my language simply because I don't have a firm grasp on expert consensus, I only have a handful of optometrist friends, and I usually like to defer to consensus.
I'm not sure why you'd think they wouldn't be honest with me: you should assume good faith.
I thought I did answer it with my first paragraph, but if that still seems odd to you we can probably chalk it up to English as a second language or to a misunderstanding.
Optometrists are not medical doctors. It's better to consult ophthalmologists (plural) on this. They are better educated and the ones that actually do all the hands-on work on your eyes
I know that. But technically, optometrists have a "professional doctorate" in optometry ("doctor of optometry" or OD), just like doctors have a "professional doctorate" in medicine ("doctor in medicine" or MD). Neither MDs nor ODs are traditional doctors, which is what you would traditionally call someone with a PhD, and not someone who takes care of your health.
I just don't happen to know any ophtalmologists, or anyone with a PhD who specializes in this, and in any case a good optometrist has overlapping expertise and concerns with ophtalmology and current research. Take it for what it's worth, no more, no less.
I'm an ophthalmologist. Optometrist are very well educated and very competent. They tend to be better at things optics related like refractions, contact lens fitting, etc. and are perfectly capable of managing bread-and-butter medical ophthalmic issues.
Ophthalmologists tend to be better at complex medical management, especially when there are systemic manifestations and own anything requiring surgical intervention.
Optometrists do a 4-year doctorate. Ophthalmologists do a 4-year MD that includes the full spectrum of medical training (gen surg, ob-gyn, neurology, etc.) and then a 1 + 3 residency that includes 1 year of general medicine or surgery and 3 years of medical and surgical ophthalmology.
There are, of course, optometrists who are very good at medical management and ophthalmologists that are very good at refractive issues (e.g. refractive surgeons). We mostly work cooperatively although things occasionally get spicy. I I enjoy working with and learning from my optometrist colleagues. I go to an optometrist friend when I need a refraction and an ophthalmologist friend for my annual.
PS.: ophtalmology residency candidates compete for an absurdly small number of seats in Canada/US, so an ophtalmologist’s opinion on optometrists should be weighed relatively heavily (they’re very smart folks). Commenter is being very humble.
Imagine doing surgery on a pile of wet tissue paper is how I’ve heard retinal surgery described. I’m no expert, but I’d bet it’s even more challenging than most brain surgeries.
On the contrary, there's nothing people love more than blaming any problems on what the kids these days are enjoying, regardless of evidence.
The evidence is actually pretty clear, what's causing this vast increase in myopia is not spending enough time in bright environments (i.e. outside) during one's formative years. In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.
If we actually cared about fixing the problem, we'd be making it easier for children to spend time outside and making outdoor environments more welcoming for them. But that would require parents to allow children some freedom, or maybe even actually make some lifestyle changes of their own, whereas the revealed preference of parents is to lock their children up indoors all day and night doing something that looks like "studying" (i.e. pointless drills).
It's purely the brightness. If you're in ambient bright light you don't develop myopia even if you're looking at nearby objects the whole time (e.g. reading books or a phone), if you're in a dim environment you still (are at statistically elevated risk to) develop it even if you're looking at distant objects. This is something they've had to keep doing bigger and bigger studies on because everyone who hears about it has the same kind of thoughts as you did.
OK. A dumb question. So I've been using dim screen brightness to my computer monitor every since I started using glasses. Should I be increasing screen brightness?
Cos I am very serious about having proper lighting on the room I work in. But always thought the screen should be dimmer than the room for some reason.
The short answer is I have no idea. As a matter of personal speculation, I doubt screen brightness makes much difference compared to the huge range that ambient light level can have (about four orders of magnitude IIRC). Most screens look bright at night even on their dimmest setting, and are too dim to read in sunlight even on their brightest setting.
Interesting. Mine has been the least possible brightness with which I can read. Just turned it up a notch to match the room brightness. Let me experiment with it for some days.
> what's causing this vast increase in myopia is not spending enough time in bright environments (i.e. outside) during one's formative years.
I'd like a source on that. AFAIK the leading factor is so called "near activities", or more specifically, lack of "far activities" (i.e. lack of looking at a distance, which makes your eyeballs get and keep proper shape and characteristics).
> In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.
Again, environment brightness, AFAIK, is way less important than the distance at which you are looking. Hence, looking at the TV is better than at your phone. And I suspect both are better than reading a paper book.
No that's not it at all. It's amazing how people in this thread act like this is a new frontier in health care or something, thinking that genetics and exposure to light are the causes.
It has been determined very conclusively that myopia is caused by spending too much time looking at close objects. That was in my highschool textbook like 20 years ago.
Yes kids should spend more time outside but it has nothing to do with bright environment.
I can say this anecdotally based on my observations of my elders in my village in India while growing up. They used to avoid getting glasses and eventually their eyesight became worse. I don't think the hypothesis that wearing glasses is causing near sightedness epidemic.
That wasn't my intention, although I imagine they do play a role.
The human eye (specifically the ciliary muscles) are most at "rest" when staring at objects in the distance.
The human eye doesn't seem to be as well-suited for staring at distance less than ~20 feet for long periods of time.
I imagine learning how to read and write in general, the shift from an agrarian society to cognitive labor, and the invention of glasses all were just as important factors.
just guesses, because they are so infrequently worn these days, is that it somehow prevents eyeball deformation due to its rigidity and so the axial elongation does not occur.
I'm a little sceptical about that theory, but my own rx did not go increase much when I wore RGPs. After that I did have some progression, but also a million other things changed, so who knows.
RGPs however, are quite distinct in that they give absolutely perfect vision. better than soft contacts by a mile. Maybe some refractive thing as well, optometrist told me numerous times under-correction would lead to further progression.
Ortho-K is popular in Asia for prevention, those are rigid lenses worn at night. Deforms cornea a little, so it's like a reversible lasik thing. So, in this case, not only its rigid lenses, they also have weird geometry. Many report significant success.
People whould wear reading glasses even before myopia. And when they do get myopia, they should NOT wear prescribed glass while reading/working, but a reading glasses that factor in their myopia.
I dont understand why people especially shortsighted people still use the same glasses for everything. Why don't octometrists know better?
People wear the same glasses for everything because it is hard remembering where your glasses are, carrying them around, and swapping back and forth every couple seconds.
You only look at things relatively close to you from 9 to 5? You don't have computers or TVs at home? A smartphone? Cooking instructions?
It's not a hyperbole, glasses are massively inconvenient to those of us handicapped without, and having to hot-swap then depending on subject is massively more inconvenient.
It's hyperbole because you consistently ignore the fact that eyes can change focus for the short term, that's like the one thing they do. It's straining your eyes for long periods, at the same focal point, such as while working, that we need to help with.
PS: you are right, maybe instead of only at the desk, just wear a "near sight" pair all the time, when you're indoor, and a far sight pair when you are out. Point is you dont have to hot swap.
This significantly underestimates the eye strain from using the wrong glasses or no glasses. "Long periods" is minutes in my case.
And yes, most will just use short-range glasses all day as their only pair, which is exactly the thing you insisted that you did not understand ("I dont understand why people especially shortsighted people still use the same glasses for everything. Why don't octometrists know better?").
Sometimes it might make sense to just ask those with the handicap rather than make baseless assumptions about their situation as an "outsider".
Why do I need glasses for reading if I'm nearsighted? Unless you mean "ignores" nearsightedness and corrects astigmatism only? (Those are what I use for computer use, when I bother to wear them.)
I don't mean literal reading glasses, just apply the same principle: glasses designated to a task, which for most people would be using computer. All prescription glasses are for your "resting" vision to be on far objects. You'd want the resting vision to be on the computer.
Well I have -2 diopters glasses for myopia, started wearing them around the age of 30 I think (I am now 44). I never use them when reading, effectively they bother me. But have to use them when using the computer monitor, otherwise it's either blurry or have to get too close for comfort. It's a continuous "put the glasses" when looking at the screen, take the glasses when scribbling a paper or reading a book / phone. Got used to it.
Also don't use them while walking, they bother me. I feel like my eyes dry out or something, very unpleasant. It's a bit blurry but don't really notice it, also -2 is not really advanced myopia. I can't read car plates from the distance but I sure see the car coming and know not to bump into people.
I'm not terribly short sighted but also can't see clearly further than about 20cm. I have to use them for everything. I think far sighted people tend to have a more usable range of functioning vision left.
If you are myopic, you are not supposed to wear glasses for reading, but most people I know do this, which just worsens it. You are supposed to be without them for as long as you can.
Yes that is if you are not advanced. One you are no longer able to read without glasses you should have a differrent prescription just for computer/reading
They do. Not just for me, but for many Americans in some study I found previous, and many people I've talked to. However there is a conflicting Philippine (iirc, or Malay) study that concludes the opposite. Most go with this latter study, though both are likely correct, myself having experienced the former.
Having explained this to my optometrists they will take me seriously and give me most any prescription I want, though unfortunately I don't exactly know what to do. I just make sure I have dedicated outdoor glasses and limit screen time with them.
I avoided wearing contacts for a while due to this but also other concerns. I think this may have limited my romantic success somewhat, at least at the time. In retrospect contacts with readers may have been the better option.
I keep holding out for LASIK but don't know how much longer I should.
> I keep holding out for LASIK but don't know how much longer I should.
I think the Holy Grail should be eye surgery that is a permanent fix. Current options wear off with age (and not that many decades at that), and then you are back to corrective lenses. There are usually very few who can qualify for another surgery later in life...and then it wears off again anyways. It's a consumable elective surgery that consumes the benefit and the body, so in my opinion it is a net loss over the long haul.
From my understanding of lasik, it basically just etches the lens on your eye.
Must people need different lenses over the years, so it's inherently a temporary fix. And one that comes with the risk of going blind and is almost guaranteed to come with various sight issues a few years after the operation such as having more issues seeing in the dark ("night blindness") etc.
Wearing contacts comes with it's own risks however, so if glasses aren't an option for the patient, LASIK isn't that dangerous.
I could've gotten the operation for free (paid by my insurance) but decided against it, as my superlight glasses really aren't that bad and the risks just weren't worth it to me.
They do ruin your eyesight. There is an experiment you can do: if you watch your screen without glasses for an hour (make sure you do not watch it from up too close, the further away you are the better, let it be a bit blurry but still readable), a weaker pair of glasses will work, too.
Is this controlled for the partially UV blocking effect of lenses though? I.e. is it the prescription in the lenses that does it or the lack of UV rat exposure?
It’s fun that one freak suggests regularly looking at sun (with closed eyes, of course), as one of his therapies for myopia. May be there’s something to it.
> the eyes require exposition to the sun to produce locally vitamin D to form themselves
I don't follow this. The articles use blood serum concentrations of Vitamin D in their methodology, are you saying there is a separate Vitamin D production/concentration in the eye's vitreous?
It is not clear if vitamin D in the blood directly affects the formation of the eye or if the creation of vitamin D directly in the eye because of the Sun exposure do so. Here is an article[0] which is easier to read than a study.
What does folks think about CRT as treatment for myopia? They are basically hard lenses that you only wear during night and stay glasses-free during day time. My understanding is that myopia doesn't go away but also doesn't get worse.
A lot of people seem to over look the fact that being nearsided or farsided is a change in focal length, not a straight degridation of vision. Someone with "perfect" 20/20 vision can't see as far as many far sided people, and can't see as small and fine details as someone nearsided. Before the invention of lenses both could be pretty valuable traits, but of course weren't super common and harder to identify at the time too.
Anecdote: I live in Asia, and when I was in middle school, AFAIR there were only 3 people (out of 40-ish) don't wear glasses including me.
Parents nowadays blame screens for short-sightedness, but the truth is back then my classmates are almost all doing reading and writing all the time, and nobody was using screens (Symbian Nokia only took off years later).
It's only me and the other two boys who spend all the time and money on online video games - the other two guys were almost score zero in every single exam.
> Parents nowadays blame screens for short-sightedness, but the truth is back then my classmates are almost all doing reading and writing all the time, and nobody was using screens (Symbian Nokia only took off years later).
Classic (i.e. in paper) reading/writing is much worse than screens.
> It's only me and the other two boys who spend all the time and money on online video games
the most important factor, AFAIK, is "outside time", i.e. the amount of "medium/far distance looking" that you do every day. A lack of it has been proven to cause myopia.
Sitting all day at school staring at books and notebooks, memorizing bunch of useless stuff and then doing same thing without any outdoor activity (with focusing eyes at longer distance) with more and more population living in urban setting, I'm shocked!
I read an article a while ago that suggested people in cities had a worst eye sights than people on the country because of the buildings and not proper distance your eye could adapt and train itself. I guess it makes sense considering there are more and more skyscrapper in Asia.
It would have been better to use “near-sightedness” instead of “short-sightedness”. The first term always means myopia. The second can mean either myopia or personality flaw.
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[ 0.29 ms ] story [ 220 ms ] threadIt seems to be a common trend that Asian countries are getting western afflictions along with westernization.
https://www.dailymail.co.uk/news/peoplesdaily/article-298798...
It seems to be a common trend that Asian countries are getting western afflictions along with westernization.
https://www.dailymail.co.uk/news/peoplesdaily/article-298798...
Not sure if they'd figured out the mechanism, but speculation was that bright light is involved in signaling the eye to stop lengthening at the right time.
IOW the cause is, basically, school. In Winter months, kids may hardly see the Sun at all, with very short days and recess often indoors (too cold, too snowy, too wet) especially as schools have seemed to grow more wary of taking kids out in poor weather, over the last few decades. Plus anything else that keeps kids indoors, sure (video games, social media[0]) but school seems to be a lot of it.
[0] And actually, the social media factor likely kicks in well after it matters. Ditto video games unless your kid becomes a gaming addict in the 3-7 age range and you just let that happen.
(My understanding is that the thing changing the shape of the eye over time is the development of the orbital socket bones — so nearsightedness and MBD could have more in common than it seems.)
I think genetics has a larger predictive effect than sunlight.
We know this isn’t true because Singapore is practically on the equator and went from less than 10% myopia to over 90% in ~50 years.
I’ll grant that with indoor malls and public transit there’s less exposure to direct sunlight, but you still can’t avoid being exposed to the sun daily in Singapore.
There is/was a very strong aversion to being outdoors, especially during peak sunlight hours (lunchtime). This compounds with both study culture and digital culture (videogames + tv + phones) and less of a celebration of sports to mean many kids get less direct sunlight than you'd think. Especially now everyone is terrified of UV
I don't think OP mentioned being in the direct sunlight, but being exposed to it (visually, as in a source of bright light). Unless you sequester yourself in a room without windows all day, to get anywhere you're likely to need to walk outside to a bus stop, an MRT station, or to get a Grab. And unless there's a tunnel connecting office buildings to hawker centers, folks probably need to walk outside to get lunch (exceptions are malls connected to food courts).
Singaporeans probably get more sunlight than say Swedes over the course of a year.
> Singaporean children had shorter reported time outdoors and lower light levels, relative to their counterparts overseas. In the current study, reported time outdoors was 1.7±1.6hours/day and average light levels were 458±228lux. In contrast, children of similar ages in Australia and the UK reported time outdoors of at least 2–3 hours/day.18 22 Likewise, higher average light levels of 1072 and 1627 lux were reported in Australian (age 10–15 years)16 and American (age 5–10 years) children,20 respectively. Differences in educational demands (homework load and afterschool enrichment classes),23 lifestyle and sociocultural factors may account for the lower reported time outdoors and light levels in Singaporean children
I can't remember exactly how many hours of exposure to sunlight the studies mentioned, but I think it was something like 2-3 hours --- and it might have to be more than just, e.g., being near a window. I'm Singaporean too, and that excerpt from that paper accords with my experience. I highly doubt that I and most of the people I grew up with had that much sunlight exposure per day.
My own personal (and very anecdotal) observations are that people really go out of their way to avoid exposure to the outdoors. Depending on your lifestyle, it is really possible to spend the day having only been outside for minutes of a day.
I think things are changing but I feel like the last 20-50 years have not really celebrated an outdoors lifestyle. Whereas my time in Europe is somewhat different in that plenty of people optimise to spend time outdoors - probably due to less oppressive weather and kids were encouraged to play outside a lot more
Although one possible nuance is that sunlight to the eyes != sunlight to the skin. In cold climates you wear thick clothes which will block out sunlight to the skin (vit D deficiency) but you may still get plenty of UV to the eyes. Throw in some mountains for distant gazing and suddenly nations that love skiing could be simultaneously vit D deficient but guarded against myopia.
Pure conjecture of course - IANA(Biologist/Opthamologist/Doctor)
I don't think historically (at least in the past 40 years) most people (barring construction workers and certain jobs) from that region were ever out for 12 hours a day in the bright sunlight.
Perhaps it is roof opening...
Their big breakthrough in understanding myopia occurred in 2008 when they studied a particular group of people who had a genetic form of myopia that’s very severe. They discovered a gene mutation that was causing the myopia.
“It turns out it was a mutation in the cone photoreceptors,” said Jay Neitz. “We then realized that it’s really just the way that the images are being encoded on the retina.”
What’s supposed to happen as your eye grows, is that things should begin to go out of focus in the periphery of your vision. That’s a signal for the eyes to stop growing.
But as long as things are still clear in the periphery, the eyes think this person must still be farsighted, because in the natural world things in the periphery are far away.
Neitz said his team was able to design a lens to make central vision clear and in focus, and give the peripheal vision much lower contrast.
“It recreates what is supposed to be going on with our eyes before we started putting all of these things in front of our face like computer screens and tablets,” he said.
After two years of wear, 85% of children wearing the innovative spectacle lenses showed less than one diopter of myopia progression.4 Moreover, the study also showed that 41% of the children wearing spectacle lenses with Diffusion Optics Technology™ showed no clinically meaningful progression in refractive error after two years versus only 17% in the control group.5“
See https://www.coopervisionsec.eu/news-two-year-clinical-trial-...
https://reviewofmm.com/the-latest-science-on-myopia-control-...
Which is obviously wrong. The main variable is the time the eye spends at a short focal length. Like every other part of the body, the eye adapts to the stresses it experiences. Focusing on nearby objects for extended periods is stressful for a normal eye and as is the case for so many stressors, the body adapts[1]. This is easily seen in that ceteris paribus a person with myopia can comfortably focus on much closer objects than someone with normal vision.
Incidentally this means that corrective lenses can actually cause myopia to progress. Contrariwise a prescription can be written such that there is an effective training stimulus to reverse myopia[2]. However, that won’t fix the decreased focal range due to age related hardening of the lens of the eye.
[1] See Selye for details.
[2] Inexplicably, most optometrists refuse to do so.
(I guess Economist must have a theme week on this...)
Then again 2 out of 3 Asians I've dated wore glasses. My first girlfriend and mine's frames touched when we kissed.
The 2 were both Americans, so it would point to a generic explanation.
Then again a geneticist friend of mine pointed out the egg that made you was actually created inside of your grandmother. So bad nutrition, due to famine perhaps, can easily affect multiple generations.
Rather depressing to think about how the grandmothers of most people likely suffered though some form of famine. It's really great to see global poverty decrease to such a level this won't be the case in 100 years.
This seems suspect, and a quick google search disagrees with you. Where did you get this information?
It isn't like your eyes are healing or anything. This isn't what we are doing with glasses because your eyes aren't injured. Using glasses is more akin to using crutches when your leg simply will never work - neurological disorders, permanent disability, and so on. The crutches help you get along. Or maybe you aren't using crutches, but instead a brace for drop foot or some other sort of support.
What you are referring to is something that will heal - an injury. And crutches are good when you are healing, too - those times you do not want to put weight on a leg. In these cases, you don't want to use crutches too long lest you have atrophy or stiffness. But this isn't like glasses at all: In this case, for eyes, you'd use things like a temporary, protective contact and/or an eye patch (There may be cases for glasses, but I'm a layperson and simply cannot think of any right now)
I don't know of any research offhand that definitely says it does or does not permanently effects your vision, but it isn't hard to get confusing or contradictory results if studies aren't well prepared specifically because your eyes can change focus slightly through concentration and can also get tired and will effect the maximum focal change possible at different times.
Whenever I switch glasses my vision gets much worse.
If I stay on a prescription for a while I'm stable.
Not a single doctor has agreed with this sentiment and I've never found any significant studies conducted that support this claim. If it were true you would expect it to have a lot more actual backing than it does, especially given how long the theory has been around now.
This geneticist should lose their degree and their job.
Not sure how a single cell from your grandmother could pass along “eggs”.
Jesus.
Your mother is born with a birth defect which causes you to be born early.
As your born early you suffer from numerous health issues.
https://mountainx.com/living/a-haunted-legacy-the-multi-gene...
>Switzer talked about how her husband, who served in Vietnam from 1968-1969, was recently diagnosed with prostate cancer. She also shared that both her son and her granddaughter were born with birth defects. Switzer mentioned higher rates of miscarriage, stillbirth, learning disabilities and asthma among the children of veterans as well. “All you vets out there, we need you to get your medical records and give them to your family. And us — we need to put down on our own medical records that our husband or father was in Vietnam and exposed to Agent Orange,” she said.
Or, maybe integration poverty causes all of your kin to eat poorly
Hope that helps
My suspicion is that staring at objects closely and under dimly lit conditions causes pseusdo-myopia which is later exacerbated by wearing glasses, causing actual axial elongation in the eyeballs through hormesis. Especially since this is what seems to happen in other animals when we dissect them.
I'm not sure why you'd think they wouldn't be honest with me: you should assume good faith.
I just don't happen to know any ophtalmologists, or anyone with a PhD who specializes in this, and in any case a good optometrist has overlapping expertise and concerns with ophtalmology and current research. Take it for what it's worth, no more, no less.
Ophthalmologists tend to be better at complex medical management, especially when there are systemic manifestations and own anything requiring surgical intervention.
Optometrists do a 4-year doctorate. Ophthalmologists do a 4-year MD that includes the full spectrum of medical training (gen surg, ob-gyn, neurology, etc.) and then a 1 + 3 residency that includes 1 year of general medicine or surgery and 3 years of medical and surgical ophthalmology.
There are, of course, optometrists who are very good at medical management and ophthalmologists that are very good at refractive issues (e.g. refractive surgeons). We mostly work cooperatively although things occasionally get spicy. I I enjoy working with and learning from my optometrist colleagues. I go to an optometrist friend when I need a refraction and an ophthalmologist friend for my annual.
The evidence is actually pretty clear, what's causing this vast increase in myopia is not spending enough time in bright environments (i.e. outside) during one's formative years. In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.
If we actually cared about fixing the problem, we'd be making it easier for children to spend time outside and making outdoor environments more welcoming for them. But that would require parents to allow children some freedom, or maybe even actually make some lifestyle changes of their own, whereas the revealed preference of parents is to lock their children up indoors all day and night doing something that looks like "studying" (i.e. pointless drills).
Cos I am very serious about having proper lighting on the room I work in. But always thought the screen should be dimmer than the room for some reason.
Thanks for taking the time to share your POV.
I'd like a source on that. AFAIK the leading factor is so called "near activities", or more specifically, lack of "far activities" (i.e. lack of looking at a distance, which makes your eyeballs get and keep proper shape and characteristics).
> In that regard cellphones (since they can be used outdoors) are a huge improvement over e.g. television.
Again, environment brightness, AFAIK, is way less important than the distance at which you are looking. Hence, looking at the TV is better than at your phone. And I suspect both are better than reading a paper book.
https://pubmed.ncbi.nlm.nih.gov/34142457/
It has been determined very conclusively that myopia is caused by spending too much time looking at close objects. That was in my highschool textbook like 20 years ago.
Yes kids should spend more time outside but it has nothing to do with bright environment.
Are you implying that cell phones could be a factor?
The human eye (specifically the ciliary muscles) are most at "rest" when staring at objects in the distance.
The human eye doesn't seem to be as well-suited for staring at distance less than ~20 feet for long periods of time.
I imagine learning how to read and write in general, the shift from an agrarian society to cognitive labor, and the invention of glasses all were just as important factors.
Your theory about 20 ft is literally correct.
Atropine is successfully used to relax the cilliary muscles.
However, there is lots of anecdata that rigid contacts don’t make your eyesight worse over time.
I'm a little sceptical about that theory, but my own rx did not go increase much when I wore RGPs. After that I did have some progression, but also a million other things changed, so who knows.
RGPs however, are quite distinct in that they give absolutely perfect vision. better than soft contacts by a mile. Maybe some refractive thing as well, optometrist told me numerous times under-correction would lead to further progression.
Ortho-K is popular in Asia for prevention, those are rigid lenses worn at night. Deforms cornea a little, so it's like a reversible lasik thing. So, in this case, not only its rigid lenses, they also have weird geometry. Many report significant success.
I dont understand why people especially shortsighted people still use the same glasses for everything. Why don't octometrists know better?
Its a horrible user experience
It's not a hyperbole, glasses are massively inconvenient to those of us handicapped without, and having to hot-swap then depending on subject is massively more inconvenient.
PS: you are right, maybe instead of only at the desk, just wear a "near sight" pair all the time, when you're indoor, and a far sight pair when you are out. Point is you dont have to hot swap.
And yes, most will just use short-range glasses all day as their only pair, which is exactly the thing you insisted that you did not understand ("I dont understand why people especially shortsighted people still use the same glasses for everything. Why don't octometrists know better?").
Sometimes it might make sense to just ask those with the handicap rather than make baseless assumptions about their situation as an "outsider".
Bad UX for switching, and my "reading" glasses have too short of a clear vision range to use at my computer without having to lean in.
It's just a comment that so wrong it's not wrong.
Prescription glasses restore your range of focus to original which is why I said it aims for looking at far objects, at relaxed eyes.
Problem with myopia is that you overwork your eyes' muscles by staying in close focal lengths too long.
Also don't use them while walking, they bother me. I feel like my eyes dry out or something, very unpleasant. It's a bit blurry but don't really notice it, also -2 is not really advanced myopia. I can't read car plates from the distance but I sure see the car coming and know not to bump into people.
And books, too.
Having explained this to my optometrists they will take me seriously and give me most any prescription I want, though unfortunately I don't exactly know what to do. I just make sure I have dedicated outdoor glasses and limit screen time with them.
I avoided wearing contacts for a while due to this but also other concerns. I think this may have limited my romantic success somewhat, at least at the time. In retrospect contacts with readers may have been the better option.
I keep holding out for LASIK but don't know how much longer I should.
I think the Holy Grail should be eye surgery that is a permanent fix. Current options wear off with age (and not that many decades at that), and then you are back to corrective lenses. There are usually very few who can qualify for another surgery later in life...and then it wears off again anyways. It's a consumable elective surgery that consumes the benefit and the body, so in my opinion it is a net loss over the long haul.
Must people need different lenses over the years, so it's inherently a temporary fix. And one that comes with the risk of going blind and is almost guaranteed to come with various sight issues a few years after the operation such as having more issues seeing in the dark ("night blindness") etc. Wearing contacts comes with it's own risks however, so if glasses aren't an option for the patient, LASIK isn't that dangerous.
I could've gotten the operation for free (paid by my insurance) but decided against it, as my superlight glasses really aren't that bad and the risks just weren't worth it to me.
Go out and play (no citations needed)!
[0]: https://pubmed.ncbi.nlm.nih.gov/30018147/
[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6951132/
I don't follow this. The articles use blood serum concentrations of Vitamin D in their methodology, are you saying there is a separate Vitamin D production/concentration in the eye's vitreous?
[0]: https://www.optometrytimes.com/view/time-outdoors-and-myopia...
I was astonished at the number of people wearing glasses in the country. Especially women.
At first I thought it was some kind of fashion statement, but it seemed to be prescription lenses for the most part.
I’m in no way saying that the article explains any of this - it’s just an observation.
https://www.paragonvision.com/crt-lenses/
https://www.aao.org/eye-health/glasses-contacts/what-is-orth...
You live in a small apartment above a large shopping mall and connected to the metro.
School is indoors, book learning is prioritised over outdoor physical activity.
Kids would spend their entire childhoods indoors.
No wonder myopia is so prevalent.
Parents nowadays blame screens for short-sightedness, but the truth is back then my classmates are almost all doing reading and writing all the time, and nobody was using screens (Symbian Nokia only took off years later).
It's only me and the other two boys who spend all the time and money on online video games - the other two guys were almost score zero in every single exam.
Classic (i.e. in paper) reading/writing is much worse than screens.
> It's only me and the other two boys who spend all the time and money on online video games
the most important factor, AFAIK, is "outside time", i.e. the amount of "medium/far distance looking" that you do every day. A lack of it has been proven to cause myopia.
https://pubmed.ncbi.nlm.nih.gov/34142457/