And Dr. Maragakis noted that any number of factors could confound the data, and it may be that wearing glasses is simply associated with another variable that affects risk for Covid-19. For example, it could be that people who wear glasses tend to be older, and more careful and more likely to stay home during a viral outbreak, than those who do not wear glasses. Or perhaps people who can afford glasses are less likely to contract the virus for other reasons, like having the means to live in less crowded spaces.
“It’s one study,” Dr. Maragakis said. “It does have some biological plausibility, given that in health care facilities, we use eye protection,” such as face shields or goggles. “But what remains to be investigated is whether eye protection in a public setting would add any protection over and above masks and physical distancing. I think it’s still unclear.”
Health care workers wear protective equipment over their eyes to protect them from droplets that can fly from coughs and sneezes, as well as aerosolized particles that form when patients undergo medical procedures, such as intubation. But for the vast majority of people, that extra level of protection probably isn’t needed if a person is wearing a mask and keeping physical distance in public spaces. There’s also the possibility of introducing risk by wearing glasses — some people might touch their faces more when they put on glasses, rather than less, noted Dr. Maragakis.
That said, more study is needed to see if the trend holds up in other study populations, said Dr. Thomas Steinemann, a spokesman for the American Academy of Ophthalmology and professor of ophthalmology at MetroHealth Medical Center in Cleveland.
“I think it’s provocative, and it’s extremely interesting,” Dr. Steinemann said.
But Dr. Steinemann noted that the study shouldn’t cause worry among people who don’t wear glasses. “It probably can’t hurt to wear glasses, but does everybody need to do that? Probably not,” he said. “I think you have to consider the practicality of wearing eye protection or a face shield. People in certain occupations, first responders, caregivers for someone who is ill, those are people who should maybe take special notice.”
The findings also raise interesting questions about how often the eyes might be the entry portal for the virus. It’s long been established that viruses and other germs can enter the body through facial mucous membranes in the eyes, nose and mouth. But the nose seems to be a main entry point for coronavirus, because it has a high number of receptors that create a friendly environment in which the virus can replicate and move down the respiratory tract.
But doctors are seeing a small percentage of patients with eye symptoms, including conjunctivitis or pink eye, which suggests the virus may also be entering the body through the eyes. Although eye symptoms are less common than other symptoms like cough or fever, various studies have reported that eye complaints can be a sign of Covid-19 infection.
Last month, researchers reported a study of 216 children hospitalized with Covid-19 in Wuhan. Among those patients, 49 children, or nearly 23 percent of the cases, had eye symptoms, including conjunctival discharge, eye rubbing and conjunctival congestion. In addition to pink eye, itchy eyes, excessive tearing, blurred vision and feeling like something is in the eye have all been described by patients with Covid-19.