Excessive screen time is changing our eyes faster than we can blink
Staring too long at screens is driving up rate of myopia, dry eye, other vision problems
Pedram Mousavi's work is all about detail, so his vision must be sharp. The luxury auto detailing studio owner says in addition to looking at glossy reflective paints, he spends hours staring at his computer and phone screens.
That's why he became concerned when he began experiencing vision problems.
At first, he said, it just felt like he had dust in his eyes.
"There was something wrong with my eyes. They were reddish and dry, dry, dry," said the 43-year-old Toronto business owner, one of more than 10 million Canadians with evaporative dry eye disease.
Eye health experts say research now links overuse of computer and smartphone screens to several progressive, irreversible eye disorders, such as dry eye disease and myopia, at rates not seen before.
By 2050, 50% of people will have myopia: WHO
"There has been an exponential increase in screen time since the pandemic," said Dr. Rana Taji, owner and medical director of Toronto Medical Eye Associates. She is one of many eye specialists who have issued online warnings about how screen overuse is changing people's eyes.
Over time, staring too long at screens can change the structure of the eyeball and lead to atrophy of the glands that keep it moist. Research is now pointing to excessive screen time for the rise in eye disorders, such as dry eye and myopia, which are becoming more common and affect more young people.
In a 2022 Statistics Canada survey, Canadians reported looking at screens an average of about 3.2 hours per day. But Canadian research released in April 2023 shows that occupational and recreational screen time averages among participants were much higher than pre-pandemic levels, with people often reporting six to seven hours per day. Participants in this study reported spending between zero and 12.5 hours per day on screens for recreation alone.
By 2050, more than half of the world's population is expected to be myopic, meaning one in every two people will be nearsighted, a finding backed by the World Health Organization.
What are myopia and dry eye disease?
Myopia occurs when the eyeball elongates from front to back. This affects its ability to bend light, which enables sharp vision. This elongation increases nearsightedness, making distant objects blurry.
While myopia or nearsightedness has a genetic component, it has been shown to progress faster in people who overuse screens.
Human eyes can also become chronically dry if the meibomian glands — a sebaceous gland that helps create protective tear film — become obstructed or atrophy. Meibomian glands secrete meibum, which is a specialized substance containing lipids that protects the eye surface.
It's different than the watery tears that flush the eye. Without a healthy tear film, eyes become dry, sensitive to light and irritated. Research has linked staring at digital devices for long periods without proper blinking to degraded gland function, even in some children.
When humans stare at screens, their blink rate decreases. Blinking activates the meibomian glands. If the eye does not blink enough, this can clog the glands and, over time, damage them.
Dr. Vivian Hill, a Calgary-based pediatric ophthalmologist and surgeon who chairs the Council on Advocacy of the Canadian Ophthalmological Society, said it's critical to give eyes a break and lubricate them by blinking.
"Whenever we're staring at a screen, our blink rate goes down to about 10 per cent of normal. So that means we're blinking once instead of 10 times," she said.
"The eyelids are little windshield wipers that have oil glands in them that basically smooth the oily tears, the moisturizing tears, over the eyeball."
Hill said when it comes to how long it's safe to stare at a screen, there's no magic number.
''No great answer exists on the exact number of hours," she said. "If your eyes feel dry, take more frequent breaks with blinking."
And keep screen time to two hours for children between the ages of five and 17, she said.
No screen time in 1st year of life, experts recommend
Dr. Harry Bohnsack, president of the Canadian Association of Optometrists, said research also shows that the more time children spend looking at screens, the more likely they are to develop nearsightedness.
"In that first year of life, children ought not to be spending any time staring at screens," said Bohnsack, who has a practice in Fredericton.
"We think that it's the lack of eye movement and refocusing from far too close ... interfering with the normal functional development of the child's eyes."
Bohnsack said this includes all screens, even television.
"We really want our children to get off the screens, especially at that younger age," he said.
How screen use affects young eyes
Taji, of Toronto Medical Eye Associates, said she treats children with vision problems made worse by screen use.
"There is an explosion of a faster progression of myopia in children. Just the other day I had a patient who was nine or 10 years old, and we've been watching him," she said. "His prescription has progressed at an alarming rate, faster than the average. We've had multiple discussions about reducing screen time and increasing outdoor activity."
When the eye is forced to stare at something too close, the brain and eye adjust or "accommodate" to increase close-up vision. Over time, the squeezing of muscles can change the shape of or elongate the eyeball. This can cause dramatic changes in eye function, especially in a child's eye that's not fully developed, Taji and other specialists said.
Dry eye disease also shows up in children.
Taji said she often sees it present in children as styes — bacterial infections in the glands at the base of eyelashes — that swell and redden. It's a tell-tale sign of gland dysfunction in children, a condition exacerbated by excessive staring at screens.
Impact of the pandemic on our eyes
When the COVID-19 pandemic arrived, people were cooped up inside — often reliant on screens for work, school and entertainment. But too much screen time harmed vision, Hill said.
She calls the pandemic the "worst" thing for myopia, as rates spiked worldwide. She also said she's seeing more cases of crossed eyes and double vision.
Slowing the progression of myopia in children is critical, as it puts the eye at risk for issues down the road, from retinal detachment to glaucoma, Hill said.
"I tell it to all the children, even the little ones: Please go outside at recess. Please go outside at lunch. Play. If you're going to be reading or on screen, make sure you take a break. Make sure that you have some exposure to natural daylight."
How do we treat these diseases?
Myopia is irreversible, but its progression can be slowed in most cases. It's usually treated with eyeglasses or contact lenses. There are also corrective surgeries, including corneal laser or intraocular lens implants. Topical drops are often used to slow the progression of childhood nearsightedness.
Meibomian gland atrophy is treated with intense pulsed light therapy, or IPL, or the use of a special needle to probe each gland to clear the 25 or 30 glands of scar tissue or obstructions.
- Limit screen use and take breaks.
- Go outside.
- Move the screen to an angle where you are not straining to look up and keeping your eyes open wider.
- Use lubrication drops with no preservatives, especially adults.
- Use the 20/20/20 rule: Every 20 minutes take 20 seconds to fully blink 20 times.