Does too much screen time damage students' eyes?

Evidence shows that myopia (short-sightedness) is on the rise, with half the world predicted to be near-sighted by 2050. Could excessive screen time be to blame?

Research into the exact links between screen time and rates of myopia is still emerging. However, scientists suspect there to be some impact of excessive screen time, particularly if children engage with screens from a young age.

“There is a genetic component to developing myopia, but we know the prevalence has increased dramatically in recent decades,” said Professor Isabelle Jalbert from the School of Optometry and Vision Science, UNSW Medicine & Health.

“It’s too rapid to be explained by genetics alone; we need to look at what’s changed in our environment, and it’s highly likely that lots of screen time is a risk factor for at least some development of short-sightedness in children.”

In myopia, the eyeball develops at a faster-than-normal rate and becomes too long, which causes distance vision to become blurry. While blurred vision can be corrected with glasses or contact lenses, once myopia sets in, it’s irreversible.

According to Jalbert, screens can cause strain to the eyes and induce symptoms of dry and tired eyes relatively quickly. A recent study she conducted found that viewing a phone screen can reduce blinking rates within the first minute in children and result in symptoms of dry eye.

“Watching a screen halved blink rates among participants, which is one of the main mechanisms for lubricating and protecting the eye,” Jalbert said.

“That doesn’t mean there is a link to developing an eye condition later on, but we’re concerned about potential long-term impacts as people spend more and more time on their devices.”

Jalbert said there are some preventative measures that can be taken to minimise the impact of digital screens on the eyes. That includes limiting daily screen time per World Health Organization guidelines — less than two hours per day for school-age children, and no screen time at all for kids under two.

“Unfortunately, researchers have found that very few children are likely meeting those recommendations daily,” Jalbert said.

Instead, Jalbert said the focus should be on getting people — particularly kids — to spend more time outdoors, which reduces the likelihood of developing myopia. However, time outdoors won’t necessarily slow the progression of myopia once it sets in.

“The more time you spend outdoors looking into the distance and wide-open spaces, the less time you spend doing near work or looking at a screen,” Jalbert said.

“It doesn’t have to be all at once; it can be at lunchtime or walking to and from school or the office. Just remember to also protect your eyes from the sunlight by wearing sunglasses and a hat.”

Optometrists generally recommend an eye examination every two years. For vulnerable populations, including those with underlying conditions like diabetes and autoimmune diseases, more frequent check-ups are advised.

“It is not realistic to tell people not to use screens at all, but we can do better when it comes to being more mindful about how screens might impact our eye health and managing the risks day-to-day,” Jalbert said.

Image credit: iStock.com/Oleksandr But