This week, The Economist reported on how myopia (short-sightedness) is now ubiquitous in East Asia. For example, one study of male high-school leavers in Seoul found that 97% were short-sighted. For decades, the scientific orthodoxy was that myopia was genetic, but it has become impossible to ignore its sharp increase in countries such as Singapore, China and South Korea as they have industrialized. So what is going on?

Many studies now confirm the link between myopia and young people’s education levels; not only their attainment, but the extent to which they participate in after-school classes and tutorials. The popular belief is that myopia can be caused by too much close-up work, such as reading and writing, and the idea was even espoused 400 years ago by the German astronomer Johnannes Kepler who also wore glasses. It feels intuitively right, and would dovetail nicely with the Alexander Technique principle that how you ‘use’ yourself affects your functioning. Yet the evidence simply isn’t there.

Instead, the scientific picture that is emerging is that myopia in young people is linked to the amount of daylight they are exposed to. Exposure to bright light appears to stimulate the production of dopamine in the retina, and this seems to help regulate the rate at which the eye grows. Too little light, and the eye grows too long to focus properly.

The answer therefore is to allow children more time outdoors, which has all sorts of other benefits. This is incidentally the message promoted by The Economist leader article on the subject.

And as far as the Alexander Technique’s ‘use affects functioning’ argument is concerned, this can I think be usefully extended to one’s environment. Spending quality time outdoors, and particularly in nature, must be considered essential to the healthy use of ‘the Self’.