Myopia epidemic affecting 90 per cent of pupils in East Asian countries is consequence of world-leading education systems.
Spending more of your life studying could cause you to lose your sight, according to UK research which found every year of education incrementally increases short-sightedness.
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.
Rather than the stereotype of bespectacled pupils being more studious or intelligent, it is the hours spent working on tasks indoors and at close distance while the eyes are developing that affects sight, they added.
Short-sightedness, or myopia, is one of the leading causes of visual disability around the world and rates are rising rapidly.
By 2050 half the world’s population, around 5 billion people, are expected to be short-sighted compared to roughly 1.4 billion people today – 10 per cent of these will have severe myopia, which carries a risk of blindness.
In high income Asian countries like Singapore, South Korea and China – which have intensive education pressures including homework at preschool level – as many as 90 per cent of people are short-sighted by the time they leave school at 18.
Half of these children are already myopic by the end of primary school, compared to 10 per cent of British children.
But the authors add that in the UK and elsewhere, towards more intensive early years education raises the length of time over which short-sightedness can become severe and more time outdoors should be prioritised.
“Our study provides strong evidence that length of time spent in education is a causal risk factor for myopia,” said Professor Jez Guggenheim from the School of Optometry and Vision Sciences at Cardiff University.
“Policymakers should be aware that the educational practices used to teach children and to promote personal and economic health may have the unintended consequence of causing increasing levels of myopia and later visual disability as a result.”
For their study, published in the BMJ today, Professor Guggenheim and colleagues recruited 68,000 British men and women who are part of the UK Biobank programme.
They looked at genetic markers which are associated with short-sightedness and staying longer in education, as well as their actually sight and education information.