By Jody Johnson-Pettit
Spending more time outdoors can reduce a child’s odds of developing myopia.
That’s one of the findings of a recent study from the University of Waterloo’s School of Optometry and Vision Science and the Canadian National Institute for the Blind.
The study found that only one additional hour per week outside can lower the odds of nearsightedness in children by 14.3 percent.
“The mechanism for why it is beneficial to be outside is not fully understood,” says Deborah Jones, interim director and clinical professor of the School of Optometry & Vision Science and clinical scientist at the Centre for Contact Lens Research. “It is thought that it might relate to certain wavelengths of light being beneficial to slow down eye growth which slows down the progression of myopia.”
There are a few ways to help increase children’s time spent outside each day including walking the dog or riding a bike. It is the brightness of natural sunlight that is beneficial rather than ultra-violet light, so it is important to use sun protection.
The study entitled, “Myopia Prevalence in Canadian School Children,” found nearsightedness, also known as myopia, increases drastically from Grade 1 to 8, with almost a third of the cases going undiagnosed and uncorrected.
“It is not fully understood, why myopia is showing up more often in younger children,” says Jones. “It can’t be ruled out that children are doing more near-activities – in particular the use of electronics such as tablets and phones.”
It is suggested that children limit near tasks to two hours per day, including time on handheld digital devices, reading and drawing.
According to the study’s research, myopia usually starts at around age 12 or 13, but is now showing up more often in kids six or seven years old.
The study estimated myopia prevalence to be six per cent in ages six through eight and increased to 28.9 per cent in children aged 11 through 13.
The Canadian Association of Optometrists recommends eye exams every year for school-aged children. Of the children who participated in the study, six percent had uncorrected myopia.
“This kind of gradual deterioration in eyesight easily goes unnoticed without regular eye exams,” says Jones.
According to the report, children of a parent with myopia have more than double the risk of developing it themselves.
“One of the biggest factors is genetic,” says Jones.
Myopia is an inherited condition known as a refractive error.
This pilot study was the first of its kind studying the general population of school-aged children in Canada.
About 170 children from the Waterloo region in Ontario participated in the study, with 17.5 percent of them being nearsighted.