Special glasses not advised for children

Blue light blocking glasses are not recommended for the prevention of myopia, experts said at a press conference on Friday.

Many parents have been buying blue light blocking glasses for their children as they are to have classes on TV or the Internet from Monday since schools need to stay closed due to the coronavirus epidemic.

Dr Zou Haidong from the Shanghai Eye Disease Prevention and Control Center said such glasses were designed to block light of shorter wavelengths, including reducing damage to the retina by blue light.

“They are mainly used to reduce macular degeneration among aging people, but their effect on preventing myopia has not been proved,” said Zou. “Children might feel the computer screen is relatively dark when wearing blue light blocking glasses and turn up the brightness. The damage to the eyes in such conditions is still unknown. So I don’t recommend children wear such glasses when reading and studying.”

Some parents are also planning to use projectors for the online classes. Zou said that to ensure children have a clear visual experience, parents have to use devices of high resolution in a proper environment.

He stressed that neither blue light blocking glasses nor projectors have been proved to be effective in preventing myopia.

“Currently, there are two ways that have been proved effective – increasing outdoor activities and reducing the time spent on continuously watching screens from a short distance,” he said.

He advised adults to look into the distance for at least 20 seconds after 20 minutes of staring at computers or cellphones, while children should further reduce continuous screen time and do eye exercises twice a day.

He said children should expose their eyes to sunlight for at least an hour a day. He also said people need not wear goggles.

“Eye conjunctiva is not directly connected with respiratory tracts, so the virus entering eye conjunctiva will not enter respiratory tracts directly,” he said. “Meanwhile, tears can also dilute the virus and are somehow antiviral. It’s very unlikely for droplets containing the virus to cause pulmonary infection via the eyes.”

But he advised people not to touch their eyes with unwashed hands because that might cause viral conjunctivitis.