Study finds a significant reduction in the risk of COVID-19 infection among those who always wear glasses

In a recent study posted to the medRxiv* preprint server, researchers analyzed the influence of the use of spectacles on coronavirus disease 2019 (COVID-19) risk in a community setting.

Background

Respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), could infect the eyes or travel through the nasolacrimal duct into the nose and lead to a viral infection. Although the relevance of SARS-CoV-2 transmission through the eyes is uncertain, people who wear spectacles might have a low risk of infection. However, only a few nations have urged eye protection to limit public transmission of SARS-CoV-2.

Prior reports have primarily focused on the impact of protective eyewear in hospital settings against SARS-CoV-2 infection and indicated that eye protection might prevent COVID-19. However, no investigations have assessed the possible preventive benefit of wearing spectacles for vision correction in the community setting against COVID-19.

About the study

In the present work, the researchers hypothesized and evaluated the use of spectacles in a community context for minimizing the likelihood of COVID-19. The hypothesis was based on previous investigations of protective eyewear against COVID-19 in healthcare settings and biological mechanisms of SARS-CoV-2 transmission via the eye. 

The authors collected the subjects' responses from the Virus Watch prospective community cohort investigation in Wales and England to a survey on the usage of contact lenses and spectacles.

Among the 58,670 volunteers of the Virus Watch cohort, the researchers invited 31,749 participants to answer the monthly survey about contact lenses and spectacle use, and 19,166 responded to this questionnaire. The questionnaire covered topics including purpose, frequency of use, and probability of using a face mask with spectacles.

COVID-19 was confirmed via self-reported positive lateral flow assays, or polymerase chain reaction (PCR) results in weekly surveys and data connection with Second Generation Surveillance System (Pillar 2 and Pillar 1). Additionally, in a subset of 11701 participants, SARS-CoV-2 infection was confirmed through monthly capillary blood investigation for SARS-CoV-2 spike (S) and nucleocapsid (N) proteins.

A multivariate logistic regression model was used to determine the probabilities of SARS-CoV-2 infection based on the purpose and frequency of wearing contact lenses or spectacles, adjusting for age, gender, occupation, and income.

Findings

The study results showed that the median age of the subjects was 63 years, and 54.6% of them were females. Of the 19,166 Virus Watch subjects who answered the present survey, 13,681 stated they used spectacles. 

Out of the 19,166 Virus Watch volunteers, 19.6% demonstrated evidence of previous SARS-CoV-2 infection. Among these subjects, 19.6% and 19.9% were males and females, respectively, indicating an absence of variation in SARS-CoV-2 infection among the two genders.

While 22.99% of people who never wore spectacles for general use had COVID-19, only 15.63% of those who constantly wore spectacles for regular use were SARS-CoV-2-infected.

The multivariate regression model controlled for gender, income, age, and occupation depicted a 15% lower chance of COVID-19 for individuals who reported wearing spectacles constantly for general usage than people who had never worn spectacles. A similar observation was found in those using spectacles always for reading and other particular activities. 

Furthermore, the authors did not find any correlation between occasionally wearing spectacles and COVID-19 protection. A decreased protective impact of spectacles against COVID-19 was observed in those reporting an interference by spectacles for wearing a face mask. This interference of spectacles in mask usage was due to the steaming up of spectacles while wearing a mask. Notably, contact lens wearers did not show any protective impact against SARS-CoV-2 infection. This was the case for different frequencies of contact lens usage.

Conclusions

The study findings demonstrated that individuals who use spectacles had a lower chance of SARS-CoV-2 infection than non-spectacle users. However, the protective effect against COVID-19 was not observed in contact lens users. In addition, a reduction in the protective effect of spectacles against SARS-CoV-2 infection was identified in those who mentioned interference of spectacles with their face mask use.

The results of the present study were representative of the community context, unlike most of the existing investigations on the topic. Moreover, data derived from the present study was controlled for probable confounders and offered a counterfactual assessment with contact lenses.

Overall, the present research indicates the relevance of the eye as a portal for SARS-CoV-2 infection. The authors found a moderate decline in the chance of COVID-19 in individuals who wore spectacles. This research extrapolated the existing evidence of the SARS-CoV-2 infection through the eyes in the hospital setting to a community context. The study results also confirmed the hypothesized biological pathways of eye protection in lowering the likelihood of COVID-19 transmission. The study findings indicated that using protective eyewear might reduce SARS-CoV-2 transmission in both healthcare and community settings.

*Important notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Shanet Susan Alex

Shanet Susan Alex, a medical writer, based in Kerala, India, is a Doctor of Pharmacy graduate from Kerala University of Health Sciences. Her academic background is in clinical pharmacy and research, and she is passionate about medical writing. Shanet has published papers in the International Journal of Medical Science and Current Research (IJMSCR), the International Journal of Pharmacy (IJP), and the International Journal of Medical Science and Applied Research (IJMSAR). Apart from work, she enjoys listening to music and watching movies.