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 in Hong Kong have discovered a skyrocketing rise in myopia, or myopia, among 709 children aged 6 to 8.
Compared to previous years, the number of diagnosed cases of myopia increased by more than 10 percent, affecting almost a fifth of the study group of children.
While it is impossible to tell from the data obtained whether this loss of 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 this risk.
What's more, recent research suggests that lack of time outdoors may be a more important indicator of myopia than even genetics. It is therefore possible that school closures and widespread lockdowns caused by the pandemic are to blame for the recent rise in myopia among children.
"While home quarantines and school closures will not last forever during the pandemic, the growing adoption and dependence on digital devices, as well as the behavioral changes caused by prolonged home confinement, could have long-term implications for the progression of myopia in the population, especially among children." researchers write in their new work.
Today in China, myopia is considered an epidemic. More than 90 percent of young people there are nearsighted, making the next generation susceptible to numerous eye diseases throughout their lives.
Every year, hundreds of thousands of schoolchildren in China undergo vision tests to track this widespread disease. Similar to recent findings in Hong Kong, this national ophthalmology program has also found significant increases in myopia on the mainland.
According to recently released data, the prevalence of myopia among 6-year-olds in China was three times higher when schools closed in 2020.
"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.
"The incidence of myopia (13, 15% in 1 year) in the previous sample was lower than in our COVID-19 group (19, 44% in 8 months, p <0.001), despite a longer follow-up - 1 year versus 8 months in the COVID-19 group, indicating that the incidence of myopia has increased during the COVID-19 pandemic, "the article says.
It is not yet clear what exactly caused this increase, but a survey showed that during the pandemic, children in Hong Kong spent 68% less time outdoors, on average from an hour and a quarter to just 24 minutes a day.
The time spent behind the screens, on the contrary, has increased almost 3 times, from 2.5 hours a day on average to 7 hours a day.
Children living in Hong Kong already spend significantly 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 the problem.
During COVID-19, not only schools and playgrounds closed, but also swimming pools, parks, campgrounds and indoor entertainment venues such as gyms and game rooms.
Therefore, the children in Hong Kong had no choice but to stay at home. Due to the aggravating factors of outdoor exposure and increased close proximity, it is possible that their eyes changed shape over the course of the eight-month study, disrupting focus and blurring distant objects.
"Although no clear connection has been found between time spent behind the screen and the progression of myopia, time spent behind the screen is itself a form of close work," the authors explain.
"Therefore, the increase in screen time may have contributed to the progression of myopia during the current quarantine period."
The study is based only on observational data, and the time with the screen and the time spent in the fresh air were provided independently.
Despite these limitations, the findings join a growing body of research showing that the global pandemic is increasing the time spent in close work, which in turn increases the risk of developing myopia.
"Our initial results indicate an alarming progression of myopia, which requires appropriate corrective action," the authors write.
The study was published in the British Journal of Ophthalmology.