Excessive screen time is changing our eyes faster than we can blink

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.

"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.

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.