A study of 6- to 8-year-olds in Hong Kong found the proportion of children with nearsightedness, or myopia, increased from 19.4% at the start of the pandemic to 35.3% eight months later.
The researchers reported in the British Journal of Ophthalmology that the average amount of time children spent outdoors fell from about 90 minutes a day to less than half an hour, and the total time they spent on close visual work increased from about 3.5 hours a day to about 8 hours, driven largely by a surge in screen time.
The study cannot prove that pandemic-related changes, such as the closure of schools, caused the higher myopia rates. Still, time spent outdoors “has been consistently shown by multiple studies” to protect against myopia, said coauthor Jason Yam of the Chinese University of Hong Kong.
“Our results serve to warn eye care professionals, and also policy makers, educators and parents, that collective efforts are needed to prevent childhood myopia.”