A new study has found wearing eyeglasses may reduce the risk of contracting Covid-19.
Researchers suggest coronavirus patients were five times less likely to have glasses than the general population, the Daily Mail reported.
The researchers said they believe this is because ACE-2 receptors, which the virus latches onto to enter and infect human cells, can be found in the eyes.
The findings of the study, from The Second Affiliated Hospital of Nanchang University in China, reinforces recommendations that healthcare workers wear eye protection.
It also highlights why preventive measures such as frequently washing hands and avoiding touching your face are seen as being important by health authorities.
The team in Nanchang looked at 276 patients diagnosed with Covid-19 between January 27 and March 13.
Thirty patients wore eyeglasses (10.9 per cent), including 16 cases of nearsightedness and 14 cases of farsightedness.
None of those diagnosed with the virus wore contact lenses or had undergone refractive surgery to correct their vision.
A total of 16 patients, all nearsighted, were long-term wearers, defined as wearing glasses for more than eight hours a day, accounting for 5.8 per cent.
For the general population, the researchers looked at a study decades ago from students between ages seven to 22 years in Hubei province, of which 31.5 per cent wore glasses for nearsightedness.
At the time of publication, those students would be between ages 42 and 57, close to the median age of 31 for the Covid-19 patients.
This means that the general population is 5.4 times more likely to wear eyeglasses daily than those diagnosed with coronavirus.
"Our main finding was that patients with Covid-19 who wear eyeglasses for an extended period every day were relatively uncommon, which could be preliminary evidence that daily wearers of eyeglasses are less susceptible to Covid-19," the authors wrote.
The researchers hypothesise that frames "prevent or discourage wearers from touching their eyes, thus avoiding transferring the virus from the hands to the eyes."
Studies have recently found that the eyes produce ACE-2, making the organs a prime target for the virus.
Coronavirus has not only been found on the surface of the eyes, but also within tears, which would transfer the pathogen.
This may explain why up to 12 per cent of patients with Covid-19 have so-called "ocular manifestations", such as redness and swelling.
"Therefore, the eyes are considered an important channel for SARS-CoV-2 to enter the human body," the authors wrote.
"Wearing eyeglasses may become a protective factor, reducing the risk of virus transfer to the eyes and leading to long-term daily wearers of eyeglasses being rarely infected with Covid-19."
In an invited commentary, Dr Lisa Maragakis, an associate professor of medicine and epidemiology at Johns Hopkins University School of Medicine, said people should not wear glasses if they do not need them.
"Although it is tempting to conclude from this study that everyone should wear eyeglasses, goggles, or a face shield in public to protect their eyes and themselves from Covid-19, from an epidemiological perspective, we must be careful to avoid inferring a causal relationship from a single observational study," she wrote.