Children who are heavy users of screens are almost four times more likely to be shortsighted, according to new Irish research.
Obese children, as well as children with sedentary lifestyles, are three times more likely to be shortsighted, compared to those with a healthy weight or who were involved in regular physical activities.
Breastfeeding for the first three months of life appears to have a protective effect against shortsightedness, with bottle-fed babies twice as likely to suffer from the condition later in childhood, the study of more than 1,600 schoolchildren found.
And children who spent less than one hour outdoors each day were five times more likely to be shortsighted than those who are out of the house for more than four hours a day during summer.
The study by researchers in Technological University Dublin and Waterford Institute of Technology looked at a mix of 37 urban and rural schools in both disadvantaged and advantaged areas across the State. All the children had their eyes examined while their parents were quizzed on the children's diet and lifestyle.
Shortsightedness has long been associated with reading and other close-range tasks, often performed indoors. However, the rise and ubiquity of electronic screen technology, even among the very young, means today’s children are focusing their eyes at short distances for longer periods than any previous generation.
Reduced daylight
Sedentary lifestyle, obesity, increased screen-time and reduced daylight exposure, as well as family history, were all associated with shortsightedness in children, the study published in the British Medical Journal of Ophthalmology found.
Children using screens for more than three hours a day were almost four times more likely to be shortsighted than those spending less than one hour on screens daily.
The difference is most pronounced among young children: 6-7 year-olds who were heavy screen users were five times more likely to be shortsighted than light users, but the margin falls to 21 per cent among 12-13 year-olds.
Co-author Siofra Harrington said while both screen activity and traditional reading were linked to myopia, the concern was that children were spending more time than ever using their eyes at close distances.
“We’re seeing a perfect storm, where children are increasingly spending their time indoors, are not physically active, and are using their eyes at short ranges,” she says.
Retinal detachment
The study does not establish a causal relationship between shortsightedness and the factors identified, but Ms Harrington would like to carry out further research tracking children’s eyesight over time to see if one exists.
Shortsightedness can have serious health consequences in later life, including an increased risk of retinal detachment, she points out. For some people, shortsightedness cannot be avoided, but the longer its onset can be delayed, the less severe it will be.
Her advice to parents and policymakers is to ensure children spend two hours a day outdoors. And since school takes place during the day, this means they may have to rethink their daily schedules.
An estimated 2 billion people in the world are myopic and this is projected to rise to 5 billion by 2050.
