"This study shows that exposure to more years in education contributes to the rising prevalence of myopia", the authors write.
The team gathered data from 67,798 men and women aged 40 to 69 years who were taking part in UK Biobank, a large, long-term study which looks at conditions such cardiovascular disease (CVD) and cancer incidence in thousands of UK residents.
The researchers analyzed the data for 44 genetic variants associated with myopia and 69 genetic variants associated with years of schooling using a technique called Mendelian randomization. Little evidence was found to suggest that myopia affected education.
As a result, they found that each year in school was linked with a decrease of 0.27 dioptres - A dioptre is a unit of measure of the power in a lens, and its positive or negative value determines the refractive power of the lens.
Longer hours of studying causes myopia or short-sightedness, a new study finds.
For more than a century, observational studies have reported links between education and myopia, but whether time spent in education causes myopia, children with myopia are more studious, or socioeconomic position and a higher level of education leads to myopia has not been known with any certainty.
To put this into context, a university graduate from the United Kingdom with 17 years of education would, on average, be more myopic than someone who left school at 16 (with 12 years of education). The level of difference between the two would mean the college graduate would need to wear glasses for tasks like driving a vehicle, notes Science Daily. One of the potential factors may be light exposure, according to Atan, adding that natural light might have a protective effect according to clues from previous research.
Experts pointed to the experience in East Asia, where schooling means early intense educational pressures and little time for play outdoors.
The research team suggest that less time spent outdoors is a possible link between education and myopia, and they recommend children spend more time outside.
"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". They acknowledge that the people in their database were generally healthier than the general population, which could lead to bias. However, there was little evidence that this could explain their findings. Children from developed East and Southeast Asian countries regularly say that they spend less time outdoors than children from Australia or the United States and randomised controlled trials have shown that more time spent outdoors during childhood protects against the development of myopia.