7 ms·

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

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.

corrral 4y ago
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.
- exceptione 4y ago
  If exposure to bright light is the primary cause of most near-sightedness, than not seeing the sun would be beneficial. I don´t get it, typo?
  - dan-robertson 4y ago
    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.
    - derefr 4y ago
      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.)
  - corrral 4y ago
    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)
- wenc 4y ago
  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.
  - doliveira 4y ago
    There's a reason why they're not just saying "it's genetics"...
    - deleted 4y ago
      [deleted]
  - barry-cotter 4y ago
    > 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.
    - wenc 4y ago
      Right with the same amount of 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.
      - lmm 4y ago
        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.
      - djtango 4y ago
        Are you familiar with Singaporean norms? 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
- irrational 4y ago
  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?
helloworld 4y ago
https://newsroom.uw.edu/news/glasses-stop-myopia-are-successful-multi-site-trial https://newsroom.uw.edu/news/glasses-stop-myopia-are-success... 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.
- xeromal 4y ago
  I love how they discovered this!
- forum_ghost 4y ago
  Failed in clinical trials? Never heard about this until now.
  - helloworld 4y ago
    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/ 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.
User23 4y ago
> 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.
cipheredStones 4y ago
Everything in this comment except "pretty interesting" is lifted word-for-word from the article - why is it framed as if it were your own comment?

corrral 4y ago

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.

exceptione 4y ago
If exposure to bright light is the primary cause of most near-sightedness, than not seeing the sun would be beneficial. I don´t get it, typo?
- dan-robertson 4y ago
  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.
  - derefr 4y ago
    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.)
- corrral 4y ago
  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)
wenc 4y ago
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.
- doliveira 4y ago
  There's a reason why they're not just saying "it's genetics"...
  - deleted 4y ago
    [deleted]
- barry-cotter 4y ago
  > 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.
  - wenc 4y ago
    Right with the same amount of 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.
    - lmm 4y ago
      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.
    - djtango 4y ago
      Are you familiar with Singaporean norms? 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
irrational 4y ago
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?

helloworld 4y ago

https://newsroom.uw.edu/news/glasses-stop-myopia-are-successful-multi-site-trial https://newsroom.uw.edu/news/glasses-stop-myopia-are-success... 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.

xeromal 4y ago
I love how they discovered this!
forum_ghost 4y ago
Failed in clinical trials? Never heard about this until now.
- helloworld 4y ago
  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/ 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.

User23 4y ago

> 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.

cipheredStones 4y ago

Everything in this comment except "pretty interesting" is lifted word-for-word from the article - why is it framed as if it were your own comment?