Wearing Eyeglasses May Protect your from Covid-19September 27, 2020
Eyeglasses Protect you from Getting COVID-19
If you haven't heard this on the news, you might enjoy the concept. A study of 300 Chinese admitted with COVID in Wuhan found that only 16 wore eyeglasses whereas some 31% of the population there have severe myopia (very common in China) and need eyeglasses. If every group of the population had equal risk, one would have expected roughly 100 folks in the cohort. That suggests an 80%, roughly, reduction of risk by wearing eyeglasses. That's huge.
But is it real and should I go out and buy eye-protection? The limits of the study are that it was observational, not prospective. (Bless the heart of the lowly ward technician whose responsibility it was to inventory patients' possessions and made the observation.). And, the researchers used data from population studies in the area to come up with their 31% having myopia. They didn't check the vision of all the patients admitted. Ok, point taken.
What does this speak to? Here is my take on the implications. I believe this is another piece of evidence that the primary mode of infection is airborne particles, whether they be droplets that fall to the ground in a minute or two (sneeze or cough) or aerosolized tiny particles (talking, singing) that float around a little longer. Either one will do it. Which is the worst has huge implications for the safety of health care workers as it takes a MUCH higher level of protection to guard against the aerosolized particles. There have been many nurse protests about lack of adequate PPE for that reason. And there have been many deaths of health workers to support that fight.
What isn't said in the article is that there is less and less evidence that COVID-19 is primarily spread by contact with surfaces. On a dry surface, the airborne particle, which is primarily water, dries out. When it is dry, the 10,000 virus particles desiccate and fall apart. They stop being infectious. It hasn't been extensively studied, but surface contamination is not the primary means of spread. Cardboard, paper, cloth, your paper mail are all forms of dry, water-absorbing surfaces.
Your eyes are moist and wet. They drain right into your nose through your tear ducts. Your nose has lots of receptors for the virus to bind to and get its lifestyle started.
WWW. What will work for me? I naturally wear glasses. The study considered that folks who wore glasses more than 8 hours a day were in the safer group compared to less use of glasses. If I didn't have glasses, with this evidence, I would try and ramp up my use of dark glasses when out in public. I am making a real effort to keep my hands off my face and my eyes, something difficult to do in ragweed season when my eyes itch. I'm better at taking an antihistamine just to control the itching for these few weeks. Would I advise you to wear glasses indoors when outside of your own home? I would. It's not that hard to do. I still take wipes with me into public restrooms and use hand sanitizer when I touch surfaces. I've stopped wiping my mail or making my packages sit outside for a day. I do wear a mask when I leave my home, but only when within 30 feet of people or in closed buildings.
References: AJMC, New York Times, JAMA Ophthalmology, UptoDate, J Virology,
1. What did this study show? Answer: In Wuhan, China a group of 300 patients had an 80% underrepresentation of COVID in eyeglass wearers.
2. Was the study constructed in a fashion to consider good, reliable medical evidence? Answer: No. It was observational, not prospective, vision was measured to see who needed eyeglasses and the incidence of eyeglasses was projected from prior, earlier studies of the population. Still, not bad.
3. What are the "implications" of this study, not yet supported by hard science. Answer: Another piece of the puzzle that supports the primary spread is moist, water-laden particles floating in the air that hit your moist eye, or nose or mouth when you breath in air contaminated with the COVID-19 from someone else.
4. Can a person make tiny droplets when just speaking? Answer: Yup.
5. When do you spray out even more particles? Answer: Singing, shouting, speaking loudly. Amp it up with coughing and sneezing.
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