New research shows that the rate of myopia among children and adolescents worldwide has tripled over the past three decades, with a particularly sharp increase since the start of the COVID-19 pandemic in 2020.
A role in British Journal of Ophthalmologywhich reviewed 276 studies published until June 2023 around the world, concluded that more than one in three children and adolescents is myopic, triple the number in 1990.
“Emerging evidence suggests a possible association between the pandemic and accelerated vision decline among young adults,” states the report, published in September.
The authors predict that if current trends continue, around 740 million children and adolescents (more than half worldwide) will be myopic by 2050.
The paper estimates that the current rate of myopia among children in Canada is approximately 25 percent. That number is lower than the international average, but is still a significant increase from the prevalence of 17.5 percent, University of Waterloo researchers concluded in a paper. published in early 2018.
“Myopia has increased dramatically during the COVID period,” said Lisa Christian, associate director of clinical practice at the University of Waterloo School of Optometry.
Christian said research suggests the trends are related to children spending more time indoors doing what is known as “close to work,” such as looking at books, computers or phone screens. The strain this puts on the eye muscles can cause nearsightedness.
“When we’re indoors, we focus on close work most of the time, we look at one place,” Christian told CBC Information in an interview. “When we are outside, we look into the distance, so we relax our eyes.”
Benefits of being outdoors
Successive studies have shown how myopia is related to very little time outdoors during childhood.
He 2018 University of Waterloo studywhich focused on children ages six to 13, found that an extra hour of outdoor time per week could reduce a child’s chance of developing myopia by 14 percent. “Time spent outdoors was the only childhood activity that had a significant impact on myopia,” he said.
Other research teams reached similar conclusions. TO Australia 2021 Study found that spending less time outdoors during childhood was associated with an increased risk of myopia in young adulthood, while a Germany 2022 Study They found that myopia in children was significantly associated with less frequent outdoor activity.
According to Christian, research suggests that children should spend one to two hours a day outdoors to protect their eyes against the onset of myopia.
And that time doesn’t have to be consecutive: Shorter periods of outdoor activity, like walking to school, being outside during recess and lunch, and playing outside after school, add up.
Not only does being outdoors give eye muscles a needed break from close work, but there is also evidence that the quality and intensity of outdoor light can protect against myopia, said Dr. Asim Ali, chief ophthalmologist at the SickKids Hospital Toronto.
“Outdoors, in the sun or even on a cloudy day, the lighting is much brighter than what we can do indoors,” he said in an interview.
The reasons behind the increased prevalence of myopia are “definitely more than just screens,” Ali added. Note that when children are indoors, it is important to provide them with bright light to alleviate visible fatigue.
a study published in January 2024 analyzed the increase in screen use among school-aged children and adolescents between 2018 and 2021, that is, before and after the COVID-19 pandemic was declared in March 2020. Their findings indicated that the proportion of young people using screens above four Daily hours increased significantly in 2020 and remained high.
The problem is bigger than glasses
Dr. Stephanie Dotchin, a pediatric and adult ophthalmologist in Toronto, says myopia shouldn’t be dismissed as a trivial issue that can simply be corrected with glasses.
“As your prescription gets higher and higher, you run the risk of other eye-related health problems throughout your life,” Dotchin said.
She says people with severe nearsightedness (a prescription of -6.00 or higher) are at higher risk of developing cataracts at a young age, as well as glaucoma and retinal tears.
All of this can result in permanent vision loss, he said.
“There is now a push in North America to treat (myopia) not just as a condition, but as a disease because of its increasing prevalence,” Dotchin said.
She advises parents to encourage their children to take frequent breaks when they are inside doing close eye work, such as reading, doing homework, or looking at a screen.
The Canadian Association of Optometrists recommends Children have at least one vision exam before starting school and have their vision checked annually from age six and up.
