The debate continues about the protective effect of eyeglasses against contracting the COVID-19 virus. Researchers from Denmark reported that their results1 were inconclusive regarding whether wearing eyeglasses is linked with a decreased risk of COVID-19 infections.
Rasmus Gregersen, MD, from the Departments of Emergency Medicine and the Center for Clinical Research and Prevention, Copenhagen University Hospital–Bispebjerg and Frederiksberg, and the Department of Public Health, University of Copenhagen, all in Copenhagen, was lead author of the study.
This cohort study included 2120 individuals who were members of the same international rescue corps during the first wave of the pandemic from June to August 2020. During that time, personal protective equipment was not recommended for the general population. The jobs that the participants filled were ambulance, health care, office, field staff positions, firefighters, and roadside assistance.
The main exposure was wearing glasses, including contact lenses and reading glasses, which was assessed in a questionnaire. Persons wearing glasses were compared with those who did not wear glasses. To adjust for potential confounders, information on age, sex, job function, and number of workday contacts were included.
The primary outcome was development of a COVID-19 infection before or during the study period.
Glasses vs. no glasses
Of the 2120 participants, 1279 were in Denmark and 841 in Sweden. Of these, 829 individuals (64.8%) in Denmark and 619 (73.6%) in Sweden wore glasses, the researchers.
“Wearing glasses,” they commented, “was inversely associated with COVID-19 infection in the Swedish cohort (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.37-0.99; p = 0.047; seroprevalence, 9.3%) but not in the Danish cohort (OR, 1.14; 95% CI, 0.53-2.45; p = 0.73; seroprevalence, 2.4%).”
Gregersen reported lower COVID-19 prevalence rates among those who wore glasses in Sweden compared with those who did not (8.1% vs. 12.6%, respectively) but not in Denmark (2.5% vs. 2.2%, respectively).
In Sweden, after adjusting for age, sex, job, and number of workday contacts, wearing eyeglasses was not associated with COVID-19 infection (OR, 0.64; 95% CI, 0.37-1.11; p = 0.11).
When the participants were stratified based on their jobs, a large difference was observed among office staff (OR, 0.20; 95% CI, 0.06-0.70; p = 0.01) but not ambulance staff (OR, 0.83; 95% CI, 0.41-1.67; p = 0.60) or health care staff (OR, 0.89; 95% CI, 0.35-2.30; p = 0.81).
“In unadjusted analyses, we identified an inverse association between wearing glasses and contracting COVID-19 in Sweden but not in Denmark,” the researchers concluded. “After adjusting for available confounding factors, an inverse association was no longer identified, thereby providing inconclusive findings whether wearing one’s own glasses is associated with a decreased risk of COVID-19 infections.”
Gregersen R, Jacobsen RK, Laursen J, et al. Association of COVID-19 infection with wearing glasses in a high-prevalence area in Denmark and Sweden. JAMA Ophthalmol. Published online August 25, 2022. doi:10.1001/jamaophthalmol.2022.3234