Insidious side effect: Lockdowns and school closings apparently have a negative effect on children’s eyesight – they increase myopia. Screenings of almost 130,000 school children in China provide evidence of this. According to this, the eyesight of six to eight year olds deteriorated by an average of 0.3 diopters in 2020 – 1.4 to three times more than in previous years. The causes could be the infrequent time outdoors and homeschooling.
The corona pandemic and its countermeasures are also affecting children around the world: schools have been closed for months since spring 2020, instead of playgrounds and physical education, there is homeschooling and in some countries even curfews. “This allowed them to spend more time indoors and in front of screens while reducing activities outside,” explain Xuehan Qian of the Tianjin University Eye Clinic and his team. In China alone, more than 220 million children were at home for months.
Why being outside is important
The problem with this is that not spending enough time outdoors and reading a lot or working at a computer screen can increase the risk of nearsightedness in children. This occurs when the child’s eyeball grows too much and the sharpest image is created in front of the retina. The growth of the eyeball is promoted by messenger substances. However, when children exercise a lot outdoors, the UVB radiation contained in sunlight inhibits the release of this messenger substance.
Qian and his team have now examined whether the corona lockdowns also affect children’s myopia in a good 123,500 school children in the Chinese city of Shandong. There, elementary school children are tested for myopia every autumn in a series check-up. This enabled the researchers to compare the results for up to five years.
Significant increase in myopia
The result: In 2020, the myopia of children and the proportion of ametropia among them increased significantly. On average, the eyesight of the six to eight year old children decreased by -0.3 diopters. “In 2020 there will be a substantial change in myopia in this age group, the researchers report. In contrast, the effect was less in the nine to 13-year-olds; their eyes only deteriorated by 0.1 diopters on average.
The proportion of nearsighted people per year of age among six-year-olds rose from 5.7 percent in the previous year to 21.5 percent in 2020, and among eight-year-olds the proportion increased from 27.7 percent to 37.2 percent. “The frequency of myopia in this age group in 2020 is significantly higher than in all previous years from 2015 to 2019,” said Qian and his team. “These changes were evident in both boys and girls and in both eyes.”
“Worry could be justified”
Scientists believe that these results suggest that the lockdown and school closings had a negative impact on children’s eyesight. “Such a substantial increase in myopia has not occurred in any other year-on-year comparison and therefore makes it probable that the cause lies in the domestic restrictions in 2020,” state Qian and his team.
Younger children in particular, in whom the eyeball is still growing and whose eyesight is particularly plastic, are particularly badly affected by a lack of outdoor activities. “To the best of our knowledge, we are providing the first evidence that the concern could be justified – at least for younger children between the ages of six and eight,” the researchers said. In the case of older children, it is not yet clear whether their eyes could deteriorate as much if they were locked down for a longer period of time.
Limit screen time and get more outdoors
The scientists recommend that all parents make sure that their children get enough exercise in the fresh air, even during lockdowns and school closings, and that the time in front of the screen is limited as much as possible. In further studies, they now want to investigate whether the worsening of myopia is reversible or permanent and how the eyesight of older children continues to develop. (JAMA Ophthalmology, 2021; doi: 10.1001 / jamaophthalmol.2020.6239)
Quelle: JAMA Ophthalmology
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