Too much screen time could harm children's eyesight, specialists warn

It's usually around this time of year that Vancouver optometrist Dr. Mini Randhawa notices children streaming into her practice with dry eyes and blurry vision.

Randhawa's optometry practice focuses on pediatrics, so an influx of children isn't unusual.

What is odd, she says, is the increasing number of kids with conditions she correlates with too much "screen time" — time in front of a phone, tablet or TV.

"The problem with screen time is it actually has some pretty significant side effects on our eyes — particularly kids' eyes," Randhawa said.

August to October are the busiest months at Randhawa's practice, as parents bring their children in to ready them for the school year.

But for some, it's also a return to normal after a long summer of lax screen time rules. And Randhawa says it's this time of year when she most sees a decline in her young patients' eyesight. 

Some eye care health professionals like Randhawa are warning that long hours in front of a screen is causing an "epidemic" of near-sightedness, or myopia, among children, whose eyes develop until they're about 20.

But not all agree that there's a direct causal link between screen time and worsening eyesight. 

The topic has garnered enough attention to prompt the Canadian Ophthalmological Society and the Canadian Association of Optometrists to put together a joint position statement on computer screen time for children. It's expected to be released by mid-November. 

A 2015 feature article in the journal Nature says there has been a "dramatic increase" in myopia in countries around the world, with China seeing the sharpest rise.

The article notes that in China, the percentage of people with myopia has risen to 90 per cent of teenagers and young adults, up from 10 to 20 per cent 60 years ago. In the U.S., the number has doubled.

Strain of near work

Some researchers say the problem isn't screen time as much as a lack of time spent outdoors. 

Vancouver ophthalmologist Dr. Jane Gardiner says the main problem with screen time is that it takes away from outdoor play.

"To say that [screen time] actually induces myopia, I don't think that's an accurate statement or a reason to tell people that they shouldn't use screens," she said.  

Theories about why outdoor time is good for children's eyesight vary. Researchers link positive outcomes to factors ranging from sunlight and vitamin D to looking at objects far away. 

Other researchers say it's the strain caused by "near-work," or looking at visual details up close — on a screen or otherwise — that is the real culprit driving myopia among children and their still-developing eyes.

Dr. Jay Neitz, ophthalmology professor at the University of Washington, is a big proponent of that theory. 

Neitz agrees that time outdoors is beneficial for developing children's eyesight, but in his view it's primarily because kids aren't usually looking at a screen when they're outside. 

'Epidemic of myopia'

He says the correlation between near-work and myopia is "irrefutable," and points to the link between the sharp rise in myopia and the increased use of electronic screens like TVs, tablets and computer games.  

"Those are the things that have changed since 1950," he said. "Basically, it's an epidemic of myopia."

At her Vancouver practice, optometrist Dr. Randhawa agrees with Neitz's diagnosis. But she says computer screens pose a particular problem for children's eyesight.

Randhawa says screens can also cause sleep disruption and dry eyes.

People looking at screens blink one fifth as much as normal, she says. And blinking helps to clean, moisturize and lubricate eyes. 

"I'm seeing a huge increase in the number of kids who are coming in with dry eyes, which has never really been a concern before," she said.

The blue light emitted by most screens is also disruptive, Randhawa says — leading to long-term damage on the eye's interior. And because blue light simulates daylight, it can also keep children from getting a good night's sleep if they're looking at a screen too close to bedtime. 

Tips to avoid eye damage

Randhawa admits there are many factors that contribute to myopia and other eye problems. And she says it's unrealistic to expect anyone, let alone children, to keep away from screens. 

Instead, she teaches her young patients what she calls "visual hygiene" techniques. These include:

• Minimizing screen time as much as possible. 
• Using bigger screens, further away.
• Taking a one-minute pause every 10 minutes to look away from screens when in use.

She also recommends using special glasses that block the blue light that most devices emit. 

Regardless of the debate concerning the cause of myopia and vision loss, most researchers agree that spending less time in front of a screen and more time outdoors is beneficial to children's eyesight.

But they also agree that's not the easiest solution in our day and age.

"Whether we like it or not we're becoming more and more dependent and forced to use these screens," Randhawa said.