Being a bookworm harms eyesight, new research suggests – with those who spend longer in education far more likely to be short-sighted.The study on more than 60,000 Britons found that those who went to university had significantly worse vision than those who left school at 16.Researchers said extra time spent reading and lack of time outdoors might explain the increased prevalence of short-sightedness among those who spent longer in education.Previous studies have shown links between education and myopia. However, it has not been clear whether those who are short-sighted become bookish – perhaps because they struggle with sports – whether years of bookishness damages vision. Every extra year in education increased the likelihood of myopia by -0.27 dioptres. Overall, a British university graduate with 17 years of education would, on average, be at least −1 dioptre more myopic than someone who left school at 16. The difference is enough to mean needing glasses for driving.The authors of the study suggested schools should try to ensure children spent more time outdoors.Experts pointed to the experience in East Asia, where schooling means early intense educational pressures and little time for play outdoors. Half of children are short-sighted by the time they leave primary school, compared with less than 10 per cent of British children.Study author Dr Denize Atan, of Bristol University, said: “This study shows that exposure to more years in education contributes to the rising prevalence of myopia, and highlights a need for further research and discussion about how educational practices might be improved to achieve better outcomes without adversely affecting vision.””Given the advantages of time spent outdoors on mental health and the protection it provides against obesity and chronic diseases, we might all benefit from spending more time outside.” This study shows that exposure to more years in education contributes to the rising prevalence of myopiaDr Denize Atan, study author The new research from the University of Bristol and Cardiff University used a technique which analyses genetic variants – to conclude that the latter is likely to be the case.The study involved 67,798 men and women aged 40 to 69 from the UK Biobank database.Researchers said their findings provide “strong evidence” that more time spent in education is a risk factor for myopia, and “have important implications for educational practices”. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.