The excessive use of computer and smartphone screens is causing several progressive and irreversible eye disorders, according to eye health experts. Studies have shown a link between the overuse of screens and conditions such as dry eye disease and myopia. Excessive screen time is also changing the structure of the eyeball and causing atrophy of the glands that keep it moist, leading to more frequent eye disorders. A recent Statistics Canada survey showed that Canadians spend an average of 3.2 hours per day on screens, but occupational and recreational screen time has increased significantly since the pandemic began. A Canadian study released in April 2023 showed that people spend between zero and 12.5 hours per day on screens for recreation alone, often six to seven hours per day. By 2050, more than half of the world’s population is expected to have myopia.
Myopia occurs when the eyeball elongates from front to back, affecting its ability to bend light and enabling sharp vision. This elongation makes distant objects appear blurry, and the condition has a genetic component, but it progresses faster in people who overuse screens. Human eyes can also become chronically dry if the meibomian glands, which help create a protective tear film, become obstructed or atrophy. Meibomian glands secrete meibum, a specialized substance containing lipids that protects the eye surface. Staring at digital devices for long periods without proper blinking can lead to degraded gland function, even in children.
When people stare at screens, their blink rate decreases, and if the eye does not blink enough, this can clog the glands and, over time, damage them. Pediatric ophthalmologist Dr. Vivian Hill recommends frequent breaks with blinking when eyes feel dry and limiting screen time to two hours for children between the ages of five and 17. For the first year of life, experts recommend no screen time at all, including television. Dr. Harry Bohnsack, president of the Canadian Association of Optometrists, said that research shows the more time children spend looking at screens, the more likely they are to develop nearsightedness.
Dr. Rana Taji of Toronto Medical Eye Associates treats children with vision problems caused or made worse by screen use, including myopia that progresses faster than average. When the eye is forced to stare at something too close, the brain and eye adjust to increase close-up vision, and over time, the squeezing of muscles can change the shape of the eye. This can lead to increased nearsightedness, making distant objects appear blurry. Eye specialists warn that excessive screen time is changing people’s eyes and recommend giving eyes a break and lubricating them by blinking. Although there is no magic number on the exact number of hours of safe screen time, it is critical to limit screen time and take frequent breaks to maintain healthy eyes.