digital eye strain and dry eyes: is all that screen time bad for you?

the impact on your eyes from digital devices has become so prevalent, there’s now a term for it: digital eye strain. cedars sinai health defines it as a group of eye and vision problems, including dry and red eyes, itchy, tearing eyes, focusing difficulties, and tired eyes – all from the use of computers and digital devices.

increase in screen time during the covid-19 pandemic

consider the impact of covid-19. a 2021  study  from western university found that screen time use in children increased by an average of 3.2 hours a day in the wake of pandemic school closures. in 2023, a study from the university of victoria in victoria, b.c. showed that occupational and recreational screen time averages among participants were significantly higher than pre-pandemic levels at six to seven hours per day. participants spent up to 12.5 hours per day on screens for recreation alone.

“the screen will not create a disease in your eye, so it’s not like, ‘oh, i should stop the computer use and i won’t be sick or have eye trouble.’ but it’s a risk factor,” says dr. lucie khouri, a montreal ophthalmologist and professor at the university of montreal. one area of specialty for khouri, who also speaks regularly on the subject at national and international conferences, is dry eyes, a common complaint that is often the result of digital eye strain. according to the canadian national institute for the blind , more than 10 million canadians have dry eyes.

the importance of blinking

when you blink, you’re spreading fresh tears across your eye surface to keep it lubricated and clear of any debris, so you prevent irritation and infection, and what you’re looking at is clearer and sharper as well. since there are no blood vessels on the surface of the eyes, tears also bring oxygen and nutrients to those surface cells to support eye function. scientists from japan have looked at blinking as a momentary state of wakeful rest to give you a mental break and improve focus afterward.

the role of tears in eye health

eye muscles under pressure

research is now linking screen overuse to myopia or nearsightedness, where your eyeball changes shape, elongating from front to back. over time, the squeezing of muscles can change the shape of the eyeball, which is especially concerning in a child’s eye that’s not fully developed. estimates suggest that over 50 per cent of the global population will be myopic by 2050. it’s usually treated with eye glasses or contact lenses, as well as topical drops.

prevention and treatment: how to counteract eye strain

eye experts repeatedly tell patients is the 20/20/20 rule, khouri says: every 20 minutes take a 20-second break to fully blink 20 times. and take breaks every hour or two away from your screen. even better, get outside to let your eyes focus on things further away and expose them to outdoor light which research shows reduces your risk of developing myopia .