In a JAMA Ophthalmology article published September 16, researchers note that, despite eyeglasses being commonly worn among the Chinese population, few patients admitted to the hospital for COVID-19 wore glasses.1 This sparked an investigation that ultimately suggests that habitual spectacle wearers are less likely to be infected with the SARS-CoV-2 virus.1 Coverage in consumer media soon brought the news, and possible misinterpretations of it, to patients around the world.
Debate Rages On
Early in the COVID-19 pandemic, eye care providers spent a significant amount of time educating patients on the safety of various forms of optical correction. Contact lenses were under fire first as a potential viral vector—a rumor that was quickly quashed by experts. As long as CL wearers follow proper care and wear protocols, they should be fine.1
In April, researchers from the Centre for Ocular Research & Education (CORE) reported that there was “no scientific evidence that wearing standard prescription spectacles provides protection against COVID-19 or other viral transmissions.”1 In fact, they speculated that switching from contact lenses to spectacles could actually increase the risk of viral transmission because of increased face touching and the fact that the SARS-CoV-2 virus can live on hard surfaces, such as spectacle frames, for hours or even days.1
Now, months later, this new study suggests the opposite: habitual spectacle wearers are less likely to be infected with the SARS-CoV-2 virus, perhaps because myopes—who are more likely to wear glasses all day—aren’t touching their face as often as presbyopes and hyperopes.2 Perhaps future studies will dive deeper into the associations between COVID-19 infection and optical correction choices.
The authors studied 276 patients hospitalized with confirmed COVID-19 in Suizhou, China, between January and March 2020. They identified the percentage of myopic patients who were habitual glasses wearers in this hospitalized population, generalizing that myopes are more likely to wear glasses all day long, while presbyopes and hyperopes may set their glasses aside more frequently, especially in social settings.1
They found that the rate of glasses-wearing myopes among confirmed COVID-19 patients was extremely low, at 5.8%. The authors compared this to an epidemiological study from 1987 that found the prevalence of myopia in a different province in China was 31.5%, and noted that in some more recent reports the prevalence in China exceeds 80%. They concluded that wearing eyeglasses more than eight hours a day may be protective against this virus.1
This unique study suggests glasses may be a successful barrier to the virus. Despite the promising finding, reality, as always, is more complex. Several experts have pointed out issues with the study, including its small sample size, the poor comparison study, the possibility of other confounding variables (e.g., education, lifestyle, age or some other unknown variable) and that the study was conducted before the importance of hand-washing and social distancing was well-known.2
JAMA Ophthalmology ran an invited commentary on the study by Lisa Maragakis, MD, an infectious disease specialist at Johns Hopkins University School of Medicine; Dr. Maragakis commented that “the observed difference […] is unlikely to have occurred by chance alone, but it does not indicate a causal relationship between wearing eyeglasses and preventing the disease.”2
The mechanism by which glasses protect against the virus could include preventing aerosol access to the conjunctiva and decreasing hand-to-eye touching. We know that the SARS-CoV-2 can cause conjunctivitis and that the virus is present on the conjunctiva and in ocular secretions.3 The presence of the virus in the permeable barrier of the conjunctiva strongly suggests that it can also be transmitted through the mucous membranes of the eye, although researchers believe this is a rare form of transmission.4
Since the death of the ophthalmologist Li Wenliang on February 7, in Wuhan, China, after conducting an exam on an asymptomatic but infected glaucoma patient, we have known that eye care providers are at risk.5 The CDC recommends eye care providers wear a surgical mask and eye protection during all exams.6
This recent study is certainly provocative, and the question of the extent of barrier protection afforded by glasses deserves further investigation. For now, we should not let controversy over glasses distract us from what we know works: universal masking, physical distancing and frequent and vigorous hand-washing.
Dr. Kuhn-Wilken is a staff optometrist at Pacific & Laser Institute in Tacoma, WA.
Note: The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.
1. Zeng W, Wang X, Li J, et al. Association of daily wear of eyeglasses with susceptibility to coronavirus disease 2019 infection. JAMA Ophthalmology. September 16, 2020. [Epub ahead of print].