[Skip to Content]

Claim CME

Coronavirus (COVID-19)

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

Educational Objective
To identify the key insights or developments described in this article

1 Credit CME

JAMA Ophthalmology

Published Online: August 25, 2022

Original Investigation

Article Information and Disclosures

Rasmus Gregersen, MD^1,2,3;

Rikke Kart Jacobsen, MSc²;

Jannie Laursen, PhD⁴;

Regine Mobech, MSc⁴;

Sisse Rye Ostrowski, DMSc^5,6;

Kasper Iversen, DMSc^6,7,8;

Janne Petersen, PhD^2,3

Author Affiliations

¹Department of Emergency Medicine, Copenhagen University Hospital–Bispebjerg and Frederiksberg, Copenhagen, Denmark
²Center for Clinical Research and Prevention, Copenhagen University Hospital–Bispebjerg and Frederiksberg, Copenhagen, Denmark
³Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
⁴Department of Global Business Quality Management, Falck, Copenhagen, Denmark
⁵Department of Clinical Immunology, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark
⁶Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
⁷Department of Emergency Medicine, Copenhagen University Hospital–Herlev and Gentofte, Herlev, Denmark
⁸Department of Cardiology, Copenhagen University Hospital–Herlev and Gentofte, Herlev, Denmark

Read article on JAMA Network

Read Article Claim CME

Key Points

Question Does wearing eyeglasses protect against COVID-19 transmission?

Findings In this cohort study of 2120 individuals who work at the same rescue corps, a lower COVID-19 prevalence was found among persons wearing glasses in Sweden (8.1% vs 12.6%) but not in Denmark (2.5% vs 2.2%). However, an association was not noted after adjusting for relevant confounding factors.

Meaning These results provide inconclusive findings regarding whether wearing one’s own glasses is associated with a decreased risk of COVID-19 infections when adjusting for confounding factors.

Abstract

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. Employees at Falck, an international rescue corps with different job functions (ambulance, health care, office, and field staff, firefighters, and roadside assistance) participated in the study.

Exposures The main exposure was wearing glasses (also including contact lenses and reading glasses), which was assessed in a questionnaire. Persons wearing glasses were compared with those who did not wear glasses (ie, nonusers). To adjust for potential confounders, information on age, sex, job function, and number of workday contacts were included.

Main Outcomes and Measures The outcome was COVID-19 infection before (positive polymerase chain reaction test) or during the study period (biweekly voluntary tests with a rapid test). The investigated hypothesis was formulated after collecting the data.

Results A total of 1279 employees in Denmark and 841 in Sweden were included (839 [39.6%] female and 1281 [60.4%] male; 20.5% were aged <40 years; 57.0%, 40-60 years, and 22.5%, >60 years). Of these, 829 individuals (64.8%) in Denmark and 619 (73.6%) in Sweden wore glasses. Wearing glasses was inversely associated with COVID-19 infection in the Swedish cohort (odds ratio [OR], 0.61 [95% CI, 0.37-0.99]; P = .047; seroprevalence, 9.3%) but not in the Danish cohort (OR, 1.14 [95% CI, 0.53-2.45]; P = .73; seroprevalence, 2.4%). Adjusting for age, sex, job function, and number of workday contacts in Sweden, wearing glasses no longer was associated with COVID-19 infection (OR, 0.64 [95% CI, 0.37-1.11]; P = .11). When stratifying by job function, a large difference was observed among office staff (OR, 0.20 [95% CI, 0.06-0.70]; P = .01) but not ambulance staff (OR, 0.83 [95% CI, 0.41-1.67]; P = .60) nor health care staff (OR, 0.89 [95% CI, 0.35-2.30]; P = .81).

Conclusions and Relevance While wearing one’s glasses was inversely associated with COVID-19 in Sweden in an unadjusted analysis, an association no longer was identified when adjusting for confounders. These results provide inconclusive findings regarding whether wearing one’s own glasses is associated with a decreased risk of COVID-19 infections.

Claim CME

Sign in to take quiz and track your certificates

Buy This Activity

Article Information

Accepted for Publication: July 4, 2022.

Published Online: August 25, 2022. doi:10.1001/jamaophthalmol.2022.3234

Corresponding Author: Rasmus Gregersen, MD, Akutmodtagelsen, Bispebjerg Hospital, Ebba Lunds Vej 40A, bygning 67, 2. sal, 2400 Copenhagen, Denmark (rasmus.gregersen@regionh.dk).

Author Contributions: Ms Jacobsen and Dr Petersen had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Jacobsen, Laursen, Iversen, Petersen.

Acquisition, analysis, or interpretation of data: Gregersen, Jacobsen, Laursen, Mobech, Ostrowski, Iversen, Petersen.

Drafting of the manuscript: Gregersen, Laursen, Petersen.

Critical revision of the manuscript for important intellectual content: Jacobsen, Laursen, Mobech, Ostrowski, Iversen, Petersen.

Statistical analysis: Jacobsen.

Obtained funding: Laursen, Iversen.

Administrative, technical, or material support: Gregersen, Laursen, Ostrowski.

Supervision: Gregersen, Laursen, Mobech, Ostrowski, Iversen, Petersen.

Conflict of Interest Disclosures: None reported.

Funding/Support: This work was financially supported by the Lundbeck Foundation (grant R349-2020-1172) and Falck A/S.

Role of the Funder/Sponsor: Falck A/S was involved in the design and conduct of the study, collection of the data, review and approval of the manuscript, and decision to submit the manuscript for publication. The Lundbeck Foundation was not involved in any parts of the study.

Additional Contributions: Jakob Riis, PhD (University of Copenhagen; CEO and president of Falck A/S), contributed to the study design (no compensation was received for study-related work). Camille Løve Andersen, BSc (project nurse at Falck A/S), contributed to data collection (no compensation was received for study-related work). Henrik Ullum, PhD (University of Copenhagen and CEO of Statens Serum Institut), contributed to study design, obtaining approvals, study initiation, and funding acquisition (compensation was not received).

AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
1.00 credit toward the CME of the American Board of Surgery’s Continuous Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.