A Dubious Claim, I Think: COVID-19 and glasses


The preliminary version of a new study from India on COVID-19 was published but has not yet been peer reviewed.  I suspect it will see revision and a different argument made to explain its results.

The study claims that people who wear glasses have one third the risk of contracting COVID-19 compared to those without.  But their argument is that wearing glasses means they touch their face and eyes less than other people.  I suspect others reading this think the same thing I do.

Risk of Corona virus disease 2019 (COVID-19) among spectacles wearing population of Northern India

Introduction

Severe Acute Respiratory Syndrome Corona virus-2 (SARS-CoV-2) spread mainly through respiratory droplets and contact routes. Long term use of spectacles may prevent repeated touching and rubbing of the eyes. Aim of the study is to compare the risk of COVID-19 in long term spectacles wearers with the risk in persons not using spectacles.

[. . .]

Results

In this study, total 58 patients showed the behavior of using spectacles continuously during day time and always on outdoor activities. The risk of COVID-19 was found 0.48 in spectacles wearing population as compared to 1.35 in population not using spectacles. The calculated risk ratio was 0.36. The protective effectiveness of the spectacles was found statistically significant (p-value .00113).

Conclusion

The present study showed that the risk of Covid-19 was about 2-3 times less in spectacles wearing population than the population not wearing those. The nasolacrimal duct may be a route of virus transmission from conjunctival sac to the nasopharynx.

I suspect that the results are right, that those with glasses are less likely to catch COVID-19.

But isn’t it more likely that the glasses are serving as a shield, protecting the eyes and preventing droplets from entering?  So yes, wear glasses, goggles or better yet a full face shield.

 

Comments

  1. blf says

    I have no idea if people who constantly wear glasses (like me!) are significantly, or even at all, less at Risk. I certainly don’t “buy” the seeming-[nonsense] hypothesis for the alleged lower Risk (e.g., @2); I’m also unconvinced by the “shield-like” alternative hypothesis, albeit in the rain (serious “droplets”!) they do provide some protection (mostly for the eyes), so it’s nowheres near as seemingly-absurd as the one postulated.

  2. Bruce says

    Is it possible that those with glasses are more likely to be more interested in or open to new information, such as by reading a lot? And that such people are more likely to take corrective action, such as getting glasses and wearing them if they noticed difficulty in reading? And that such people are mire likely to accept medical recommendations such as social distancing and wearing masks?
    If these all apply, then there could be a true correlation between glasses and safety that has very little to do with eyes.

  3. invivoMark says

    Nonsense, glasses acting like a face shield isn’t the explanation. It is NOT the case that 2/3 of infections are transmitted through the eyes. Almost all infections are transmitted through the airway.

  4. lochaber says

    My first thought was about what the rate of glasses-wearing in India is…

    I believe there is still some pretty extreme poverty there, and could it just be more like people who can’t afford glasses are more likely to contract COVID, for various reasons?

  5. says

    I wasn’t inferring that glasses offered total protection. It’s a combination of factors that determine the rate of transmission (how many carriers, population density, personal habits, etc.).

    What multiple medical bodies and NGO agencies have said is more than “don’t touch your face”. They said don’t touch your eyes, nose and mouth, because you can contract it through the eyes.

    https://www.umms.org/coronavirus/what-to-know/prevention-safety/protect/not-touch-face

    https://health.clevelandclinic.org/how-to-actually-comply-with-the-dont-touch-your-face-advice-from-health-experts/

  6. lumipuna says

    I wear glasses, and find they’re very helpful in making a standard medical mask sit tightly on my face. I understand this is crucial for the filtering function, assuming your mask has any significant filtering ability in the first place. I also feel the mask (unlike glasses) helps me to not touch my face that much, in addition to having spray cover and (some) filtering function.

    I sometimes wonder about people who wear makeup – do you learn to not touch your face much, to not smudge the makeup, or does it just not smudge that easily?

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