Astigmatism in students has increased 50 percent during the pandemic as pupils spend an extra 30 to 60 minutes on electronic devices due to the suspension of in-person classes, researchers from the Hong Kong Polytechnic University found.

Researchers tested 112 students aged between eight and 10 in October 2018 and another 173 students in June 2020.

Both groups studied in the same primary school.

They found that while only 34.2 percent of students tested in 2018 had astigmatism, the figure increased to 56.6 percent for the students tested in 2020.

Researchers concluded that this means an almost 60 percent increase in astigmatism among primary students over the course of two years.

The university also found that among the batch of students tested in 2018, the percentage among them who have astigmatism doubled by 2020.

Indeed, among the 38 students tested in 2018, only 34.2 percent of them had astigmatism but two years later, 73.7 percent of them had astigmatism, researchers said.

Jeffrey Leung Tsz-wing, research assistant professor from the university's school of optometry, said suspending in-person classes was to blame.

"Our survey given to students found that they spent between 30 and 60 more minutes after class to use mobile phones or tablet computers during the suspension of in-person classes," Leung said.

He said previous studies showed that such a reading environment could cause astigmatism, while using mobile devices for a long period of time will worsen the situation.

Researchers also found that children with spacious homes are less likely to have serious myopia while those living in cramped homes are more likely to suffer from it.

Postdoctoral researcher Choi Kai-yip said that in cramped spaces, children's eyes have to shift focus frequently which worsens their myopia.

A mother said she noticed that her son's eyesight had worsened after the government first suspended in-person classes in January 2020.

"Although teachers will allow them to take a break from time to time, they still sit behind the screen for a longer time, which makes my son's astigmatism more serious," she said.

A primary five student admitted that he used to play basketball with his friends before Covid-19 hit Hong Kong.

However, he can only play with his tablet computer now as basketball courts are closed.

Leung suggested students look at objects that are 20 feet away for 20 seconds after focusing on screens for 20 minutes.

He also called on teachers to avoid using text and photos that are small in size to prevent students from getting too close to their screens.

Jeffrey Leung

Online school 'a blur' for primary kids