In a finding that's being dubbed 'nerd immunity', researchers say people who wear glasses could be two to three times less likely to contract COVID-19.
The virus behind the disease, SARS-CoV-2, has been detected in people's eyes, and the World Health Organization says it can be contracted by "touching a contaminated surface and then touching your eyes, nose or mouth before washing your hands".
Scientists in India looked at 304 COVID-19 patients who'd been hospitalised in Kanpur Dehat, a district in the country's north.
Less than one-fifth of them wore glasses, compared to around 40 percent of the adult Indian population, the researchers said, citing earlier studies.
That fewer people wearing glasses were treated for the virus than would be expected suggests wearing them offers some protection, they concluded.
"Touching one’s nose and mouth is significantly reduced when wearing a face mask properly. But wearing a face mask does not protect the eyes from getting the viral infection through respiratory droplets and self-inoculation," the study, published online, said.
"The conjunctival mucosa may be the initial site of infection because it is directly exposed to external pathogens."
The virus infects our cells by latching onto enzymes called ACE-2 - these are present in the eye.
While not yet peer-reviewed, the findings back up a previous study carried out in China near the beginning of the pandemic.
"Among a group of 276 patients admitted to a hospital with laboratory-confirmed COVID-19, the proportion of the patients who reported routinely wearing eyeglasses more than eight hours per day was lower than in the general population," that research, peer-reviewed and published in JAMA Ophthalmol, found.
"The authors conclude that wearing eyeglasses more than eight hours per day may be protective against SARS-CoV-2 infection, and they hypothesize that this may be due to eyeglasses acting as a barrier that reduces the frequency with which people touch their eyes."
Also early in the pandemic - around the same time New Zealand went into its first - and to date, only - level 4 lockdown, doctors in the US urged people who wear contacts to switch to spectacles to reduce the chance of transferring the virus into their eyes.
"Nerd immunity," one Twitter user quipped on hearing the latest news, thousands of other users of the site liking the tweet.
