Results of a new study published in the peer-reviewed medical journal of ophthalmology show a strong link between screen time and the risk of developing myopia commonly known as shortsightedness or nearsightedness.
The study found that spending more than one hour a day on screens started to increase the chances of myopia significantly with the risk of this complication of the eye where sufferers can see nearby objects clearly but struggle to see things far away going even higher when screen time exceeded four hours per day.
The researchers led by Ahnul Ha, an ophthalmologist based at Seoul National University, analyzed 45 studies covering over 335,000 people where they evaluated the dose-response association of time spent on digital screens with the risk of short-sightedness.
According to the findings, for every extra hour spent on screens daily, the risk of developing short-sightedness increased by 21% and this was seen across all age groups, from toddlers to adults even though young children aged between two and seven years showed a particularly strong association.
The risk of myopia was higher when people used a combination of screens including phones, tablets, computers, TVs rather than just one type of device.
According to Ahnul, this study suggests that reducing screen time alone may not be enough to prevent myopia. Instead, balancing screen use with outdoor activities might be a better approach. For children, the researchers say limiting screen time to around one hour per day could be a safe threshold as more than four hours per day significantly raises the risk of developing myopia.