MYOPIA, or near-sightedness, is a condition whereby images from distant objects entering the eyeball are incorrectly focussed slightly in front of the retina, usually due to elongation of the eyeball. This condition is currently reaching epidemic proportions around the world with more and more people developing the condition, and at an earlier age.

The standard solution is to precribe corrective eye-glasses (it’s a great time to invest in Johnson & Johnson) but what is actually driving this disease? Common theories include “near work” like studying, the rise of iPhones, computer games and other tasks that cause us to continually focus close up.

But new research suggests that the cause is actually lack of sunlight, in particular UV-B. Children who spend 3 hours in bright sunshine per day have significantly lower rates of the condition. Australian children, who live in naturally brighter daylight conditions, enjoy lower rates than their Asian counterparts. Exercise and near work seem not to be a factor.

Interestingly, over 100 years ago William H Bates invented some steps to help improve eye-sight and, although he admitted he didn’t know why it worked, one of his steps was to expose the eye to the brightness of day.

A very good article with references here: