Why do so many Asian kids wear glasses? And why are we always nearsighted, rather than farsighted?
There are two typical explanations that people generally accept. First, that it’s genetic and tied to Asian genes. Second, that Asian parents make Asian kids read so much that they mess up their eyesight. The genetic explanation is widespread in the Asian American community; I know at least one person who wanted to marry out as a way of helping her kids’ eyesight. The “too much reading explanation” is also widespread: I remember WAY back when in the early blogosphere–before PUA and LASIK surgery were widespread–one Asian American male website even went as far as to recommend that Asian men, in order to boost their success with the ladies, read books “only when necessary!”
But now there’s a new explanation: lack of sunlight.
“Humans are naturally slightly long-sighted. We see that in rural populations all round the world. But when you start intensive schooling, and spend little or no time outdoors, you get this dramatic rise in myopia. In some East Asian cities 80-90 per cent of children are affected – and governments and the World Health Organisation are very worried about it.”
“The idea that ‘reading makes you short-sighted’ has been popular for a couple of hundred years. But recent data shows that the time spent indoors is a more important factor. Children who read a lot, but still go outdoors, have far less myopia.”
Professor Morgan explained that myopia is essentially an eye that has grown too long, and once it is too long, you can’t shorten it again: “So you have to stop it happening in the first place.
“Our hypothesis is that the light intensity experienced outdoors – which can be hundreds of times brighter than indoor light – causes a release of dopamine, which is known to block the growth of the eyeball. This prevents it taking on the distorted shape found in myopic people. We are now testing this idea.”
According to the findings, just a few more hours spent outdoors each day can protect children’s eyes from the burden of glasses.
This explanation is probably the most common sense explanation I’ve read. The genetic explanation is shaky–my four grandparents all have or had better eyesight than me. The “too much reading” explanation is also shaky; I know lots of well read Asian people with perfect vision. Most spend lots of time outdoors. Also, Asians as a group do very well in sports that require better-than-perfect eyesight like golf, archery, and riflery. These sports usually take place outdoors, where they are likely to get that dopamine burst while practicing.
It probably also makes sense because you’re more likely to “shorten” your eyes when you’re outdoors. How many indoor activities require the same distance viewing as locating a golf ball or shooting a target?
What do you think? How is your eyesight? And what do you think of the sunlight theory? (Note to Alpha and Mojo–do you both have perfect eyesight? I think people in law enforcement have to be able to shoot without glasses, right? Did you both spend lots of time in the sun while growing up?)