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Article misses the mark a little bit. "Outdoors" preventing myopia isn't about focusing distance, it's about light levels. Dimmer light makes the eye think it i

Article misses the mark a little bit. "Outdoors" preventing myopia isn't about focusing distance, it's about light levels. Dimmer light makes the eye think it isn't done growing, so it grows more. You can replicate those light levels indoors, if you're bloody minded enough to do so. It's somewhat expensive but for a tech-enabled crowd not too difficult. You need about 10x to 100x the lighting most people are satisfied with indoors, and you need to turn it on whenever you're in the room and leave it on between sunrise and sunset. This is easiest with timers and automation. The most important thing about all of this is to realize that children NEED outdoor recess sometime between the hours of 10am and 2pm every day. They don't have to be directly exposed to the sun, but they need to be in an environment with >1000 lux, more is generally better, for a number of hours. This will prevent their growing eyes from continuing to grow indefinitely. We know this because there was an intervention in Taiwan, which has extremely high myopia levels in children (80%+ last I heard), and it dropped myopia from ~80% to ~35% in the intervention group. That's an astounding effectiveness for something free.

joak 1y ago
Interesting, it seems really likely that more light indoors should be good. Do you have a reference, a scientific study on the topic? Thanks!
- jaggederest 1y ago
  Here's a couple from a random search for the convenience of the forum: https://pubmed.ncbi.nlm.nih.gov/29371008/ https://pubmed.ncbi.nlm.nih.gov/29371008/ https://reviewofmm.com/light-as-a-tool-for-myopia-control/ https://reviewofmm.com/light-as-a-tool-for-myopia-control/ I can't find the site that I read a while ago, it was very similar to the myticker.com site that was posted the other day for heart disease but focused on myopia.
  - devinplatt 1y ago
    Thanks for sharing this! I've never heard of this research, but it sounds very promising. I also found this Guardian article from a Google search: https://www.theguardian.com/world/2025/mar/01/shortsighted-taiwan-may-have-lessons-for-the-world-as-a-preventable-disease-skyrockets https://www.theguardian.com/world/2025/mar/01/shortsighted-t...
- walterbell 1y ago
  It's difficult for artificial light to compete with full-spectrum natural daylight from an infinitely distant light source (sun). See previous attempts at sunlight simulation indoors.
SoftTalker 1y ago
I have fairly bad myopia (-6) and I was outside a lot as a kid. I don’t buy this argument, at least not universally.
- alanbernstein 1y ago
  Practically nothing in health science is universal, your anecdote does not disprove anything.
- lazyasciiart 1y ago
  And I had fairly bad myopia before I could read or had ever seen a computer, would you like to reject the argument that reading or screens are relevant as well?
cosmic_cheese 1y ago
I've read a number of anecdotes about benefits of bright, full-spectrum indoor lighting and I'm increasingly sold on the idea. The only thing that makes me hesitant is the extreme unpleasantness of direct high brightness artificial light. I wonder if an indirect lighting setup of similar brightness could be as effective.
- jaggederest 1y ago
  It is. The best I've seen make use of essentially bright overcast levels of lighting, so more like 2000 lux, and it's extremely pleasant. This guy has a pretty compelling version: https://www.youtube.com/watch?v=6bqBsHSwPgw https://www.youtube.com/watch?v=6bqBsHSwPgw If you look at his scatter pane, that's where I would go. There are companies that sell similar lights retail, but they're perhaps 3x as expensive.
owenversteeg 1y ago
I'm not sure why you're convinced that focusing distance is irrelevant. Everything I've seen indicates that it is the combination of focusing distance and light level. Also... 100x the lighting indoors strikes me as quite difficult? Do you have any examples of a realistic setup?
- lazyasciiart 1y ago
  Because studies that controlled for focus distance (ie compared children reading indoors v children reading outdoors) seemed to show that focus distance did not have an impact.
  - owenversteeg 11mo ago
    Late reply, but most of the pro-focusing-distance crowd agrees that it’s time in peak sun, plus a fairly small number of daily “reps” of near-far focusing that is sufficient. In other words, kids could spend 99% of the time outdoors just reading a book, and the handful of glances at a tree in the distance, stop sign, bird, etc would be sufficient. Furthermore, as I mentioned to a sibling comment, even if it is just the bright light, with no influence from the focusing (which I doubt!) the only practical way to get that light is outdoors.
- fogj094j0923j4 1y ago
  Solving focus distance is expensive. If you could prevent this with something cheap, why not ?
  - owenversteeg 11mo ago
    The intervention that most advocate for is shifting kids’ breaks to be outdoors during peak sun hours. This is free ($0.) You get 100k lux, high CRI, flicker free light with no power or setup requirements. You also get birds, trees, buildings etc in the distance as “infinity” focus targets, also for free. (Reminder that “infinity” is actually fairly close!) This approach is also proven to improve myopia rates. Custom water-cooled ultra-powerful indoor lighting setup as suggested by sibling comment: $30k/small room (far focus not included)
skandinaff 1y ago
I wonder, wouldn't this mean that in nordic countries, where in winter get less than 6 hours of sunlight in total, and where that sunlight is mostly obstructed by heavy clouds, would be the place with most myopia in the world? For example in Latvia where I grew up, winters last from november to march-april, the nights are long, and it can be months without any sunlight. And it gets darker once you go further north - Finland, Norway, Sweden. But back in my preschool, we had 1-4 kids per 30 in the class, with any eye problems. I myself was among those few who had hypermedia, some even got rid of it by age 10-13. And if I look at the my parents, and grandparents - even fewer had need for eye correction.
- 4gotunameagain 1y ago
  Genetic adaptation of humans is a thing. One way to test it out would be the rates of myopia of people from lower latitudes that have migrated to the nordics.
  - skandinaff 1y ago
    Valid point. I guess then in Canada they could have a lot of such cases, as it has been a major destination for migration. In any case, sounds like an good topic for a research paper
YeGoblynQueenne 1y ago
>> Dimmer light makes the eye think it isn't done growing, so it grows more. Does that mean that populations in places with more sunlight (e.g. close to the equator) have less myopia than populations with less (e.g. close to the arctic)?
- jaggederest 1y ago
  Yes, and the difference is pretty significant, but early childhood schooling rates are more significant than latitude alone. https://nap.nationalacademies.org/read/27734/chapter/5#29 https://nap.nationalacademies.org/read/27734/chapter/5#29
Fire-Dragon-DoL 1y ago
That's interesting. I seem to be the only one around my circle who like bright environments (my work area uses 2 2400 lux lamps). I find most environments too dark. And I'm the only one who doesn't wear glasses, lol

joak 1y ago

Interesting, it seems really likely that more light indoors should be good. Do you have a reference, a scientific study on the topic? Thanks!

jaggederest 1y ago
Here's a couple from a random search for the convenience of the forum: https://pubmed.ncbi.nlm.nih.gov/29371008/ https://pubmed.ncbi.nlm.nih.gov/29371008/ https://reviewofmm.com/light-as-a-tool-for-myopia-control/ https://reviewofmm.com/light-as-a-tool-for-myopia-control/ I can't find the site that I read a while ago, it was very similar to the myticker.com site that was posted the other day for heart disease but focused on myopia.
- devinplatt 1y ago
  Thanks for sharing this! I've never heard of this research, but it sounds very promising. I also found this Guardian article from a Google search: https://www.theguardian.com/world/2025/mar/01/shortsighted-taiwan-may-have-lessons-for-the-world-as-a-preventable-disease-skyrockets https://www.theguardian.com/world/2025/mar/01/shortsighted-t...
walterbell 1y ago
It's difficult for artificial light to compete with full-spectrum natural daylight from an infinitely distant light source (sun). See previous attempts at sunlight simulation indoors.

SoftTalker 1y ago

I have fairly bad myopia (-6) and I was outside a lot as a kid. I don’t buy this argument, at least not universally.

alanbernstein 1y ago
Practically nothing in health science is universal, your anecdote does not disprove anything.
lazyasciiart 1y ago
And I had fairly bad myopia before I could read or had ever seen a computer, would you like to reject the argument that reading or screens are relevant as well?

cosmic_cheese 1y ago

I've read a number of anecdotes about benefits of bright, full-spectrum indoor lighting and I'm increasingly sold on the idea. The only thing that makes me hesitant is the extreme unpleasantness of direct high brightness artificial light. I wonder if an indirect lighting setup of similar brightness could be as effective.

jaggederest 1y ago
It is. The best I've seen make use of essentially bright overcast levels of lighting, so more like 2000 lux, and it's extremely pleasant. This guy has a pretty compelling version: https://www.youtube.com/watch?v=6bqBsHSwPgw https://www.youtube.com/watch?v=6bqBsHSwPgw If you look at his scatter pane, that's where I would go. There are companies that sell similar lights retail, but they're perhaps 3x as expensive.

owenversteeg 1y ago

I'm not sure why you're convinced that focusing distance is irrelevant. Everything I've seen indicates that it is the combination of focusing distance and light level. Also... 100x the lighting indoors strikes me as quite difficult? Do you have any examples of a realistic setup?

lazyasciiart 1y ago
Because studies that controlled for focus distance (ie compared children reading indoors v children reading outdoors) seemed to show that focus distance did not have an impact.
- owenversteeg 11mo ago
  Late reply, but most of the pro-focusing-distance crowd agrees that it’s time in peak sun, plus a fairly small number of daily “reps” of near-far focusing that is sufficient. In other words, kids could spend 99% of the time outdoors just reading a book, and the handful of glances at a tree in the distance, stop sign, bird, etc would be sufficient. Furthermore, as I mentioned to a sibling comment, even if it is just the bright light, with no influence from the focusing (which I doubt!) the only practical way to get that light is outdoors.
fogj094j0923j4 1y ago
Solving focus distance is expensive. If you could prevent this with something cheap, why not ?
- owenversteeg 11mo ago
  The intervention that most advocate for is shifting kids’ breaks to be outdoors during peak sun hours. This is free ($0.) You get 100k lux, high CRI, flicker free light with no power or setup requirements. You also get birds, trees, buildings etc in the distance as “infinity” focus targets, also for free. (Reminder that “infinity” is actually fairly close!) This approach is also proven to improve myopia rates. Custom water-cooled ultra-powerful indoor lighting setup as suggested by sibling comment: $30k/small room (far focus not included)

skandinaff 1y ago

I wonder, wouldn't this mean that in nordic countries, where in winter get less than 6 hours of sunlight in total, and where that sunlight is mostly obstructed by heavy clouds, would be the place with most myopia in the world? For example in Latvia where I grew up, winters last from november to march-april, the nights are long, and it can be months without any sunlight. And it gets darker once you go further north - Finland, Norway, Sweden. But back in my preschool, we had 1-4 kids per 30 in the class, with any eye problems. I myself was among those few who had hypermedia, some even got rid of it by age 10-13. And if I look at the my parents, and grandparents - even fewer had need for eye correction.

4gotunameagain 1y ago
Genetic adaptation of humans is a thing. One way to test it out would be the rates of myopia of people from lower latitudes that have migrated to the nordics.
- skandinaff 1y ago
  Valid point. I guess then in Canada they could have a lot of such cases, as it has been a major destination for migration. In any case, sounds like an good topic for a research paper

YeGoblynQueenne 1y ago

>> Dimmer light makes the eye think it isn't done growing, so it grows more. Does that mean that populations in places with more sunlight (e.g. close to the equator) have less myopia than populations with less (e.g. close to the arctic)?

jaggederest 1y ago
Yes, and the difference is pretty significant, but early childhood schooling rates are more significant than latitude alone. https://nap.nationalacademies.org/read/27734/chapter/5#29 https://nap.nationalacademies.org/read/27734/chapter/5#29

Fire-Dragon-DoL 1y ago

That's interesting. I seem to be the only one around my circle who like bright environments (my work area uses 2 2400 lux lamps). I find most environments too dark. And I'm the only one who doesn't wear glasses, lol