The myopia boom (2015)

My wife is co-authoring a review paper on this topic with the group from Zhongshan. The rise in myopia prevalence is really quite staggering, especially among asians. It's a long article, but the essential point is that insufficient time spent in bright light >10k lux (roughly corresponding to being in shade on a bright day) during early childhood increases the risk of developing myopia. Normal eye growth requires dopamine which is released in a circadian fashion, which requires exposure to…

I always thought it was because all of the "far away" stuff is outside and a person who spends 90% of their time indoors never has to look at anything far away. What are the rates of shortsightedness among people living in dense forests (or some other cramped outdoor environment)?

Its a very well studied dataset in (graduate) Stats. So many contingency tables where you correlate onset of myopia - myopia vs Asian/non-Asian, myopia verus Male/Female, with/without computer, w/wo smartphone, w/wo outdoor time, w/wo myopic parents, on & on. If you know how to run a ChiSq, you can look at some 2x2 tables here. You can convince yourself with 1 line of R. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1771677/ Or if you want someone else to run the analysis & just skip to the…

Children need to spend around three hours per day under light levels of at least 10,000 lux to be protected against myopia. This is about the level experienced by someone under a shady tree, wearing sunglasses, on a bright summer day. (An overcast day can provide less than 10,000 lux and a well-lit office or classroom is usually no more than 500 lux.) Here were I live, we do not get almost any direct sunlight from October till March -…