'Don't forget to blink': Optometrist offers advice for increased screen time

Between Zoom calls, helping kids with their e-learning and browsing the online inventory of a favourite store, many people are spending a lot more time staring at screens during the ongoing COVID-19 pandemic.

And you might be starting to notice it.

Kirsten North is an Ottawa-based optometrist and a policy and research consultant with the Canadian Association of Optometrists, and she said she's seeing an increase in how much dry eye and eye strain people are experiencing, based on the phone calls she's getting.

Those can be signs of too much screen time, she said.

"Your eyes will start to feel gritty, sandy, burning, irritated. They can get red. Dry eyes can actually be very watery, that's what happens to me," she explained.

Why do screens cause dry eye?

When a person is looking at a screen, they don't blink as often, said North.

"And if you're not blinking as often, you're not refreshing that surface, you're not squeezing the little oil glands that need to put the oil in your eye."

Your body might react by producing reflex tears, she explained.

"Those are the tears that pop up when something insults the surface of your eye. Reflex tears are very, very watery, there's a lot of them and they don't really do anything to moisturize the eye. They're meant to flush things out."

It's the base tears, the ones that sit in a person's eyes all the time, that North said people aren't getting enough of when they look at screens.

"[They] have all the good fats in them, and your immune cells, and the nutrition and everything that maintains the surface of your eye."

It's important to try and resolve dry eye, said North, because it's a disease that can impact the clarity of someone's vision and long-term comfort if it's allowed to persist.

What can people do about it?

North said it's critical to take breaks, and that she urges her patients to follow the 20/20/20 rule.

"Every 20 minutes, take a 20 second break from a screen and look 20 feet away," she explained.

And remember to blink.

"Sometimes that's all I need to tell my patients. Don't forget to blink while you're staring at something. And that goes for reading newspapers and books as well. We know the blink rate slows down a certain amount, about 30 per cent when you're reading and it slows down another 30 per cent when you're reading from a screen or something that's self lit."

North noted that there haven't been any studies done on humans to figure out if blue light coming from screens can damage a person's eyes. But, she's read research done on lab animals and retinal cells, and started to wear her own blue light filtering glasses on a regular basis.

"I feel like my eyes are relaxed when I'm looking at a screen. It cuts it down, a little bit of the brightness. And I know psychologically that it's cutting out the blue rays that might be causing some damage."

What's known for sure about blue light is that it impacts a person's sleep cycle, North added.

"The intense blue light that comes off of screens mimics the sun, and the sun is our body's signal to wake up and so if you're doing that late into the evening, it's still signalling to your brain to produce all of your wake up chemicals."

If something's off, call your optometrist

And if you think something is amiss, North urges you to contact your optometrist even during the pandemic.

Optometrists are allowed to see patients for urgent situations. Otherwise, North is fielding calls and emails from her patients, and her group practice in Ottawa is starting to do video consultations this week. 

"It's not as good as an in person exam, there's certainly tests that I can't do. But there's a lot that I can," she explained. 

She has also started initiating contact with some of the patients she knows she still won't get to see for a long time. 

"It's breaking my heart that I'm not doing what I love to do, which is taking care of people's vision."