Currently, 30-50 per cent of adults in the United States and Europe are myopic, with levels of 80-90 per cent reported in school leavers in some East Asian countries.
To find out whether more time spent in education is a causal risk factor for myopia, the research team from the Bristol Medical School used Mendelian randomisation (MR) applied to a large, population cohort, known as the UK Biobank.
Researchers based at the University of Bristol and Cardiff University in the United Kingdom set out to determine whether education is a direct risk factor for myopia, or myopia is a causal risk factor for more years in education.
Analysing genetic information in this way avoids some of the problems that afflict traditional observational studies, making the results less prone to unmeasured (confounding) factors, and therefore more likely to be reliable.
The researchers found that although genetic predisposition was a more powerful predictor of nearsightedness, years of education were strongly and causally linked to the condition. The true causal effect was suggested to be even stronger in Mendelian randomization analyses (-0.27 dioptres/year). This proposes that a UK University graduate with 17 years in training would be one dioptre more myopic than a person who left school at 16 with 12 years of education.
A study published just last month by the University of Edinburgh which looked at more than 300,000 participants also found that needing to wear glasses is linked to a higher level of intelligence.
"This evidence suggests that it is poor light rather than reading per se that damages your eyes, and has been one of the main drivers for recent investment in bright light classrooms to protect against myopia in southeast Asia".
"Myopia has been associated with higher levels of educational attainment for more than a century", said co-author Denize Atan, a consultant senior lecturer at the University of Bristol.
A new research based on genetic data reveals that spending more time studying in school can indeed have a negative effect on people's eyesight.
Consultants pointed to the expertise in East Asia, the place education means early intense instructional pressures and little time for play open air.
The authors of the study suggested schools should try to ensure children spent more time outdoors.
"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". But there was insufficient evidence that this could explain the findings.