Does studying too much make you nearsighted? What researchers are learning about myopia

More and more people worldwide are becoming nearsighted. One new study suggests that the number of years they spend in school could be a factor.
More and more people worldwide are becoming nearsighted. One new study suggests that the number of years they spend in school could be a factor. THE CANADIAN PRESS/AP, Patrick Semansky

There might be something to the stereotype of the nerd with glasses. According to new research, nearsightedness is related to education.

A study published Wednesday in the BMJ found that the more years a person spends in school, the more likely they are to be nearsighted, or myopic.

According to study co-author Jeremy Guggenheim, professor in the School of Optometry and Vision Sciences at Cardiff University, the researchers were able to determine that it was education that caused myopia, and not the other way around – that people with myopia were more drawn to books.

Researchers are very interested in the question of what causes myopia because rates have exploded worldwide.

Nearly 30 per cent of the Canadian population is myopic, according to the Canadian Association of Optometrists. Rates are rising and it’s appearing in younger and younger children.

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WATCH: An Edmonton optometrist describes the growing issues he sees in kids due to an increase in time on screens over the last five to 10 years.

Click to play video: 'Eye problems caused by screen time'
Eye problems caused by screen time

In some East Asian countries, 80-90 per cent of children are myopic by the time they leave school, the study says. A recent paper predicted that by 2050, half of the world’s population will be nearsighted.

“It’s certainly interesting that they’re saying that the longer you spend in education the more likely you are to be myopic,” said Debbie Jones, a clinical professor in the University of Waterloo’s School of Optometry and Vision Science.

Why you need glasses

Scientists aren’t really sure what causes nearsightedness, though recent research has uncovered some evidence, she said.

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Genetics plays a role. If you have myopic parents, there’s a good chance you will have those genes.

“There have also been more than 150 genetic variants identified that confer an increased risk of myopia,” said Guggenheim. However, right now scientists don’t really know why these genes increase the risk, other than they affect the light-sensitive area of the retina.

There also seems to be an association between the amount of time a child spends outside and their likelihood of developing myopia. Research that associates time spent in school with poor eyesight could fit into this, as school typically means a lot of time spent indoors staring at a workbook or screen. Many East Asian cultures emphasize educational achievement, which could correlate with their high rates of myopia, suggested Jones.

Her own research found that for each additional hour a child spent outside per week, their chance of being myopic fell by 14 per cent.

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They’re not sure why though. There’s some evidence that sunlight itself has a beneficial effect on the eye, she said. And there’s evidence that focusing on a variety of objects near and far helps too.

“You imagine a kid kicking a soccer ball around, they’re looking at their feet, they’re looking ahead at the net, they’re looking into the distance. So they’re constantly changing that focal range,” she said.

She also suspects that screen time and mobile devices have something to do with the rise in myopia.

“When I was a kid, my near activity was reading a book or doing my homework. But now, I could read a book, do my homework and then pick up a tablet and play a game.”

How to stall myopia

It’s important to stop the rising rates of myopia, researchers say. Not only are glasses inconvenient and expensive, but very poor eyesight – a prescription of -6 or more – is associated with a number of serious issues like glaucoma, retinal detachment and myopic maculopathy, which can result in vision loss.

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“That’s the big scary part of it, is the number of people with the high prescriptions, because the high prescriptions lead to the pathological complications, which can lead to visual impairment later in life,” said Jones.

Some estimates suggest that 10 per cent of the world’s population could be strongly myopic by 2050.

“It’s a huge number. It’s a massive burden on health care. And on the individuals, obviously.”

But there are things you can do for your child to lessen or delay the onset of myopia, she said. “A non-myopic young child should spend time outside. The recommendation is at least 90 minutes a day.”

Singapore, which has one of the world’s highest rates of myopia, has an ongoing public health campaign to encourage more outdoor play to protect against nearsightedness. The country’s Health Promotion Board now says that the rates of myopia among primary students have stabilized.

If your child is already myopic, there are options like hard or soft contact lenses and eye drops that can slow the progression of their myopia and potentially keep them from getting into that riskier high range, said Jones.

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And, regular eye exams can help to ensure that you catch any potential problems when they occur.

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