Short-sightedness among young children is becoming more common because they are spending too much time staring at screens, eye hospitals are warning.

There are no exact national figures but the eye departments at hospitals across the country are reporting a clear upward trend in the number of young children with problems.

“It has been going on for years and it’s only getting worse,” Maastricht University  child eye specialist Jilke Beinsberger told Nu.nl. “We think that in a couple of years over 50% of teens will need glasses.”

Orthoptist Lieke Gouma of the Rotterdam eye hospital said waiting lists are growing for children who need glasses because they have trouble reading what’s on the blackboard.

Young children or teens develop myopia or short-sightedness when they are too close to screens or books, causing objects in the distance to become blurred.

According to Gouma, shortsightedness is not caused by the light emitted by the screens but by the distance to the eyes. “It is much calmer for the eyes if devices are not held up close but because a phone is small children tend to do exactly that. And they want to get a good look at the details of games and videos.”

Experts advise parents to limit screen time and encourage children to alternate looking at their screen with other activities.

They should also teach their children the 20-20-2 rule, which means they watch the screen for 20 minutes and then train their eyes on distant objects for the same amount of time. They also advise two hours of playing outside a day because daylight helps the development of healthy eyes.