More than one-third of children and adolescents worldwide are nearsighted.

More than a third of children and adolescents worldwide are nearsighted, a figure predicted to surpass 740 million by 2050, the largest study ever found.

These alarming figures have sparked calls to limit screen time and increase physical activity for children.

The link between nearsightedness and screen time

Myopia is not just a vision problem, it also reflects a modern lifestyle that is deeply affecting children's health.

According to Bhavin Shah, a myopia specialist at Central Vision Opticians (UK), one of the key factors that promote myopia in children is working at close range for long periods of time.

“When children frequently focus their eyes on close objects like books or digital screens, the eyes are forced to constantly adjust. This prolonged focusing has been shown to accelerate the progression of myopia. And when children hold devices too close to their eyes for long periods of time, the condition becomes even more severe,” says Bhavin Shah.

Professor Chris Hammond - pediatric ophthalmologist and consultant at Guy's and St Thomas' NHS Trust (UK) added that, in addition to genetic factors, the two main causes of myopia are frequently working at close range and lack of time outdoors.

Notably, “near work” is not limited to electronic device use, but also includes traditional academic activities. “Even excessive reading, especially when held too close to the face, can be a factor in making children more susceptible to myopia,” Shah notes.

Additionally, several recent studies have shown that: “The lockdown period due to the Covid-19 pandemic, combined with a spike in screen time and lack of outdoor exercise, has led to a significant increase in myopia cases in children.”

Professor Hammond added that myopia has long been a serious problem in urban East Asia. “Myopia rates in adolescents were as high as 90%, even before screen devices became widespread. This may be related to an overburdened academic education system from an early age,” he said.

“Although further research is needed, it is clear that spending too much time indoors, focusing on close objects, and lack of natural light contribute to the problem of myopia. Therefore, limiting screen time, especially for young children, is a reasonable and necessary measure,” he concluded.

According to Shah: “Many parents still consider myopia as simply a matter of 'wearing glasses and that's it', not knowing that progressive myopia can increase the risk of serious eye diseases in adulthood, such as retinal detachment, glaucoma or cataracts.”

Shah also believes that the medical industry needs to change its mindset from “treating” to “controlling” myopia. “We need to make more public about modern treatment options like slow-adaptation glasses, Ortho-K, or multifocal contact lenses, which slow the progression of myopia instead of simply correcting vision,” he said.

Dr Annegret Dahlmann-Noor, a paediatric ophthalmologist at Moorfields Eye Hospital (UK), points out a deeper challenge: “Modern urban lifestyles are causing children to have less and less exposure to outdoor space, a very important factor in slowing the onset and progression of myopia.”

With myopia on the rise in children, what can parents do to help prevent their children from developing the condition?

When talking about simple but effective measures to prevent and slow the progression of myopia in children, Professor Chris Hammond said: “Children need to be exposed to natural light, at least 14 hours a week outdoors, whether playing sports, going for a walk or simply enjoying nature.”

Additionally, he stressed the importance of controlling screen time, especially in the early years:

- Children under 2 years old: should completely avoid screen devices.

- Children from 2 to 5 years old: no more than 1 hour per day.

- From 6 to 12 years old: should be limited to 2 hours per day.

Along with time control, device usage habits also need to be properly guided, he advised: “A simple principle that parents can teach their children is the 20-20-20 rule, which means that after every 20 minutes of reading or looking at a screen, children should look about 6 meters away for at least 20 seconds to rest their eyes.”

Professor Hammond particularly encourages parents to actively create healthy living habits with their children, such as stepping away from screens, turning off the TV, putting away phones and going for walks, cycling or playing sports together. This is not only good for children's eyesight, but also reduces the risk of obesity, increases physical fitness and improves family connection.

Finally, if a family member has myopia, regular eye exams are important: “In cases where there is a genetic factor, have your child's eyesight checked at least once a year for early detection and timely intervention.”