Nearsightedness is associated with a number of eye problems. People often become nearsighted as children, and the condition seems to be caused by a combination of genes, not spending enough time outside, and many years of schooling.
Researchers have found five genetic variants that make a person more likely to become nearsighted as they stay in school longer.
These results were published in the open-access journal PLOS Genetics today by a team led by Jeremy Guggenheim of Cardiff University, United Kingdom.
Nearsightedness is linked to a number of eye problems, which makes it the most common cause of permanent vision loss in older people.
However, children are particularly vulnerable to becoming nearsighted, which appears to be caused by a cocktail of factors including heredity, lack of exposure to natural light, and prolonged indoor activity.
Genetic studies have found more than 450 genetic variants that are linked to a higher risk of nearsightedness. However, only a few of these genetic variants have been shown to increase the risk of nearsightedness in people who also have certain lifestyle factors.
In the new study, genetic and health information from more than 340,000 people with European roots was used.
They looked at the whole genome to find genetic variations that make people more likely to become nearsighted in combination with intensive schooling.
The study found five genetic variations that, the longer people stayed in school, especially those who had graduated from college, gradually increased their likelihood of developing nearsightedness.
Three of these variations were previously unidentified, whereas two were discovered in studies of East Asian cohorts, where about 80% of children develop myopia.
In comparison, roughly 30% of Western children suffer myopia.
The findings, according to the researchers, offer fresh insights into the biological processes that underlie nearsightedness, but further study is required to comprehend how those processes combine with dietary and lifestyle choices to produce the disease.
Guggenheim says, myopia is the leading cause of vision problems that can’t be fixed, and it’s also the main reason why people need glasses or contacts.
“Building on our previous research linking education and myopia,” they identified “5 genes associated with myopia development whose effects are amplified by additional years spent in education.”
Source: 10.1371/journal.pgen.1010478
Image Credit: Tim Graham/Getty Images
