Do glasses protect against COVID-19 or make you more vulnerable to the disease? What about wearing contacts? The first few months of the COVID-19 pandemic were confusing for people who wear corrective lenses. First, a national ophthalmological society said that contact wearers should switch to glasses if they could, to avoid spreading infection by touching their eyes. Later, a commentary in a medical journal said that wearing glasses might increase the risk of COVID-19, because wearers touch their faces to adjust their frames during the day.
In September 2020, a study was published based on data from Suizhou Zengdu Hospital in Suizhou, China, about 90 miles from Wuhan, where the virus was first reported. The researchers observed that fewer people hospitalized with COVID-19 wore glasses than might be expected based on the percentage of adults in China who wear glasses. The study found that wearing glasses all day protected people from COVID-19 infections.
That study got media attention, including an article in The New York Times. However, because it was a study that was based on the researchers’ observations rather than an experiment, it was missing some of the pieces that medical doctors look for when deciding whether they let a research finding inform the way they treat their patients, such as a control group.