A recently published study looking at 276 patients in the Suizhou Zengdu Hospital in Suizhou, China showed that those who wore glasses for more than eight hours a day were at significantly lower risk of getting COVID-19 than those who did not wear glasses. Only 16 (less than 6 percent) of those patients being studied wore glasses, in comparison to the 31 percent of the local population who wear glasses.
But does this mean that wearing glasses can help protect us against the coronavirus?
Before we all rush down to the optician’s, it is worth noting that this is just one study, the sample size was very small and it only showed an association – not a direct cause and effect – between wearing glasses and COVID-19 infection rates. To draw any firm conclusions from this would be entirely premature, but there are some things we can take note of.
According to the Medical Journal of Virology, the eyes may be an important route of entry to the body for the coronavirus. We know the virus spreads mainly through respiratory droplets; when someone coughs, sneezes, talks or even breathes, tiny droplets containing the virus are propelled through the air in search of another host, usually entering through the nose or mouth. But there have been increasing reports of coronavirus patients having eye symptoms such as conjunctivitis (an infection of the outer eye).
The eyes have a moist protective layer around them called a mucus membrane. The insides of our noses and mouths have similar membranes lining them. If the coronavirus manages to land on one of our mucus membranes, it can pass through it and infect us. So it makes sense that the eyes can act as a portal of entry for the coronavirus.
Theoretically, wearing glasses forms an extra barrier in front of our eyes, protecting them from an infected respiratory droplet. Healthcare professionals wear goggles in high-risk medical settings for the same reason. But goggles are different – they offer a tight seal around the whole eye area from splashes and droplets, whereas glasses usually just offer protection from the front and leave the sides, tops and bottoms of the eye susceptible.
For this reason, wearing glasses must not be thought of in the same way as wearing safety goggles. The Centre for Disease Protection and Control (CDC) does recommend appropriate protective eyewear in high-risk workplaces, but goes on to say that “workers should understand that regular prescription eyeglasses and contact lenses are not considered eye protection”.
Another way the virus can infect us is via our hands. It is known that the coronavirus can stay on surfaces such as tabletops and door handles for up to 24 hours. If these infected surfaces are then touched by an unsuspecting person who then goes on to touch their mouth, nose or eyes, then they may infect themselves. This is why handwashing is so important.
People who wear glasses may be less inclined to touch their face and, more specifically, rub their eyes and introduce the virus this way. Some doctors have even gone as far as to advise their patients to avoid wearing contact lenses in favour of glasses. Contact lenses can irritate and dry eyes out, making it more likely that the wearer will adjust them by touching the eye. If they have not washed their hands recently, then they may be harbouring the coronavirus and infect themselves. Those who do insist on wearing contact lenses should follow proper lens cleaning routines.
Currently, there are no plans to advise the public to wear glasses to help protect them, and one study is not going to change that. Our most effective weapons in the fight against coronavirus – until a vaccine is found – are still to physically distance, wash our hands regularly and wear a face covering when appropriate. Although eye symptoms are much less common than the usual symptoms of a cough, fever and change in sense of smell and taste, it is clear that the eyes are looking (excuse the pun) to be an increasingly important route by which the coronavirus may enter the human body. Further research is needed into the role of glasses in protecting us.