Can I do it till I need glasses?

One of the more bizarre public health-related phenomena I have come across is that more years of education are associated with nearsightedness. The linked article is a bit arcane -- the point of it is to rule out that there is a genetic predisposition to getting educated which is also associated with myopia. It turns out there isn't, and ejumacashun really does seem to cause people to become nearsighted. This article in The Independent is friendlier to lay readers.

This is not a trivial or even modest effect -- it's actually huge. "The difference is so pronounced that if the average person who left school at 16 had 20/20 vision, the average university graduate would legally need glasses to drive, researchers from Bristol and Cardiff Universities said," according to The Independent.

I'm happy to say that I personally was spared this fate, despite my highly excessive education. In fact I now use reading glasses because, like most people, I have become slightly far-sighted with age. Nevertheless in parts of Asia, where children are exceptionally studious, the prevalence of myopia is now something like 90%. Unfortunately, it doesn't just mean that you need glasses -- it increases the risk of blindness and other problems.

This does not seem like sufficient reason to get less education. However, it is a good reason for more recess. Apparently exposure to the much brighter outdoor light mitigates the problem. It's not just that kids are concentrating on reading, it's that they are doing it in relatively dim light. Since getting outdoors and engaging in physical and social activity is good for you anyway, let's make sure we don't skimp on it.