There are many consequences of the current global pandemic that we did not foresee, and visual impairment in children may be one of them. Over the past year, researchers from Hong Kong have found a rapid increase in myopia, or myopia, among 709 children aged 6 to 8.
Compared to previous years, the number of diagnosed myopia cases increased by more than 10 percent, affecting nearly a fifth of the study group of children.
While it is not possible to tell from the data whether this loss of far distance vision is directly related to the pandemic, it is known that being outdoors reduces the risk of myopia in children, while doing “close work,” such as reading, writing or looking at screens, tends to increase that risk.
Moreover, recent research suggests that lack of outdoor time may be a more important indicator of myopia than even genetics. So it’s possible that school closures and pandemic widespread blockages are to blame for the recent rise in myopia among children.
“Although home quarantines and pandemic school closures will not last forever, the increasing adoption of and dependence on digital devices and the behavioral changes caused by prolonged home confinement may have long-term implications for myopia progression in the population, especially among children,” the researchers write in their new paper.
In China today, myopia is considered an epidemic. More than 90 percent of young people there are nearsighted, making the next generation susceptible to numerous eye diseases during their lifetime.
Each year, hundreds of thousands of schoolchildren in China undergo vision tests to track this widespread disease. Similar to recent results in Hong Kong, this national ophthalmology program has also revealed a significant increase in myopia on the mainland.
According to recently released data, the prevalence of myopia among 6-year-olds in China was three times higher during the 2020 school closure.
“Such a significant myopic shift has not been seen in any other year-by-year comparison, so the reason may lie in the unusualness of home confinement in 2020,” said the report, which was published earlier this year.
Results from Hong Kong, which tracked myopia during COVID-19, now support these findings.
“Myopia incidence (13.15% at 1 year) was lower in the previous sample than in our COVID-19 group (19.44% at 8 months, p<0.001) despite a longer follow-up of 1 year versus 8 months in the COVID-19 group, indicating that myopia incidence increased during the COVID-19 pandemic,” the article says.
It is not yet clear exactly what caused this increase, but the survey showed that children in Hong Kong spent 68% less time outdoors during the pandemic, going from an hour and a quarter to just 24 minutes a day on average.
In contrast, time spent in front of screens increased nearly threefold, from an average of 2.5 hours a day to an average of 7 hours a day.
Children living in Hong Kong already spend considerably less time outdoors than in other parts of the world. There just isn’t much fresh air to play in this dense city, and the pandemic has only exacerbated this problem.
During COVID-19, not only did schools and playgrounds close, but also swimming pools, parks, campgrounds and indoor recreational facilities such as gyms and game halls.
Therefore, children in Hong Kong had no choice but to stay at home. Due to the aggravating factors of being outdoors and working harder up close, it is possible that the shape of their eyes changed during the eight-month study, throwing off their focus and causing distant objects to become blurry.
“Although no clear link was found between screen time and myopia progression, screen time itself is a form of near work,” the authors explain.
“Therefore, increased screen time may have contributed to myopia progression during the current quarantine period.”
The study was based on observational data only, and screen time and outdoor time were self-reported.
Despite these limitations, the findings join a growing body of research suggesting that the global pandemic is increasing the amount of time spent at nearsighted work, which in turn increases the risk of developing myopia.
“Our initial findings suggest an alarming progression of myopia that requires appropriate remedial measures,” the authors write.
The study was published in the British Journal of Ophthalmology.
