Association of COVID-19 Infection With Wearing Glasses in a High-Prevalence Area in Denmark and Sweden.

Importance: Observational studies have indicated that glasses might protect against contracting COVID-19 through reduced airborne and contact transmission.

Objective: To investigate the association between wearing one's own glasses with contracting COVID-19 when adjusting for relevant confounders.

Design, Setting, And Participants: This cohort study was conducted during the first wave of the COVID-19 pandemic (June to August 2020) in Denmark and Sweden, where personal protective equipment was not recommended for the general population at the time.