Myopia and a prescription to slow down progression

By Nina Yan

According to recent research, nearsightedness in Canadian children increases approximately fivefold from Grade 1 to Grade 8, with roughly a third of the cases going undiagnosed and uncorrected.

Myopia, or nearsightedness, occurs when the structure of the eye causes light rays to focus at a point before the retina. Close objects look clear but distant objects are harder to distinguish and appear blurred.

A team from the University of Waterloo’s School of Optometry & Vision Science and the CNIB found that the incidence of myopia increases from 6 per cent in children aged six to eight to 28.9 per cent in children aged 11 to 13. According to the World Health Organization, the prevalence of myopia is “increasing globally at an alarming rate” and can increase the risks for vision impairment.

"Historically, myopia started at age 12 or 13, but now it is showing up more often in kids six or seven years old,” said Dr. Mike Yang, lead investigator and clinical scientist with the Centre for Ocular Research & Education (CORE) at the School of Optometry & Vision Science. “Our eyesight as a population is deteriorating and at a much younger age."

Myopia typically continues to progress until the late teenage years. Since it starts earlier in children today, they may experience a much greater decline in their eyesight over a lifetime compared with previous generations.

"One of the big problems of being myopic is that your risk of complications, such as retinal degeneration and detachment, increases,” said Deborah Jones, co-lead investigator on the study and a clinical professor at the School of Optometry & Vision Science. “The higher your prescription, the more at risk you are for complications that can lead to vision loss later in life."

According to the report, genetics plays a significant role in myopia. A child’s risk of developing myopia is doubled if a parent has it. However, the study found that reducing screen time and spending one additional hour per week outdoors significantly lowers the odds of children becoming myopic by 14 per cent.

The researchers plan to extend their pilot study to populations nationwide, looking at eye health within different ethnicities and environmental settings.

Watch CBC’s recent TV coverage of this research, featuring Jones: