3 ms·

I can't find the link but I seem to remember a study found that exposure to sunlight (at least the level found on an overcast day) was required for ~4 hours per

I can't find the link but I seem to remember a study found that exposure to sunlight (at least the level found on an overcast day) was required for ~4 hours per day to prevent myopia. This link had been suspected previously but they found a mechanism of action. The eyeball itself would release regulatory chemicals at night after the daytime exposure that inhibited growth of the eyeball. Since myopia is most often caused by the eye being slightly too large this seems like a plausible explanation. It certainly makes more sense than the previous theory about spending too much time indoors - that somehow you would spend too much time focusing closely since distances indoors are limited.

oolongtea 9y ago
The article you're referring to might be this one: http://bjo.bmj.com/content/early/2017/06/12/bjophthalmol-2017-310292 http://bjo.bmj.com/content/early/2017/06/12/bjophthalmol-201... (Alas, it's not Open Access) I also remember reading an earlier news article in Nature on this exact topic: https://www.nature.com/news/the-myopia-boom-1.17120 https://www.nature.com/news/the-myopia-boom-1.17120
sowbug 9y ago
That's fascinating. I didn't see this exact point in the Nature article linked below, but is it as simple as your body needing bigger eyes to see in the dark?