Do People With Glasses Have a Covid-19 Edge?
A new study published today in the journal JAMA Ophthalmology suggests that daily glasses wearers might be less susceptible to Covid-19. While the findings are compelling for people who wear glasses, don’t get too excited just yet. The study is very small and only really shows that in a sample of 276 people with Covid-19 in a hospital in Suizhou, China, the proportion of people who wore glasses regularly (over eight hours a day) was smaller than that of the general population.
This study is caveat city!
A research group of 276 people is considered extremely small. The researchers’ observation is that among those Covid-19 patients, 16 were nearsighted and wore glasses. The proportion of people with nearsightedness in the Hubei province is 31.5%, which is much higher than the proportion of people with Covid-19 who had nearsightedness in the hospital. So the researchers identified a small but interesting trend that fewer people with vision problems were among their 276 patients than would be expected based on the prevalence of nearsightedness in the surrounding community. It stands to reason that perhaps wearing glasses protected people from the virus in some way.
But it’s important to note that the study did not actually show that wearing glasses cuts down on the risk of getting Covid-19. That’s not to say the findings are not worth follow-up — they certainly are. But this particular study does not say much for the general public at this moment.
Evidence of ocular transmission of Covid-19 has not been well studied, and the primary way that Covid-19 is believed to spread is through respiratory droplets from person to person. That’s not to say the virus doesn’t spread through the eyes — it can. If infectious droplets landed on your eye, you could be susceptible to infection. It’s logical that perhaps a person wearing glasses would have a barrier to prevent this from happening. In health care settings where health workers are potentially coming in contact with multiple people with Covid-19, eye protection is already a critical part of personal protective equipment; people on the front lines often wear goggles or face shields. Dr. Anthony Fauci has said that goggles and face shields make logical sense as a Covid-19 barrier. But whether that barrier would make a substantial difference in a person’s daily risk of getting Covid-19 (if they are not coming into regular and close contact with people who may have Covid-19) is unclear. The evidence in favor of mask wearing versus the evidence in favor of eye protection is not the same.
“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,” writes Lisa L. Maragakis, MD, MPH, the senior director of infection prevention at the Johns Hopkins Health System in an accompanying editorial to the report.
Maragaki points out that wearing glasses could be associated with an unknown or unmeasured factor associated with Covid-19 risk. Maybe people who wear glasses wash their hands more often, for example. If another factor is responsible for the findings, Maragaki says “we would be incorrect to conclude that wearing eyeglasses reduces a person’s susceptibility to Covid-19 or to recommend that people should begin wearing eye protection in public to prevent Covid-19 acquisition.”
So, what should be taken away from these findings? The study, which Maragaki calls “provocative,” raises some possibility — though notably not proof — that the use of eye protection in the general public can offer some degree of Covid-19 protection, but much more research is needed to determine if there’s any real, incremental benefit to wearing eye coverings in addition to other measures that are known to work, like wearing a masks or physical distancing. That being said, if you want to wear your glasses or get some goggles because it makes you feel better, by all means do so. It might offer you some additional protection, though mask wearing and distancing is probably already enough.