Glasses wearers are up to three times less likely to catch COVID-19, a study by researchers at NPCD Centre, Kampur Dehat in Northern India, have found.
Touching the face, nose, mouth and eyes after coming into contact with the virus could lead to infection, but people who wear glasses rub their eyes less, according to researchers in India. They estimate this makes them two to three times less likely of being infected, as "repeated touching and rubbing of the eyes" with contaminated hands may be a "significant route" of transmission.
The researchers studied 304 people (223 male, 81 female) in a hospital in northern India between 26 August and 8 September. They were aged between 10 and 80 and all reported COVID-19 symptoms. The participants filled out questionnaires about their vision and glasses-wearing habits. Some 19% reported wearing glasses most of the time.
"An individual has the habit of touching his own face on average 23 times in an hour and his eyes on average three times per hour," the study states. "The present study showed that the risk of COVID-19 was about two to three times less in spectacles wearing population than the population not wearing those."
The researchers said tear ducts could be the route of transmission of the virus, carrying it into the nasal cavity. They said those who wear glasses for more than eight hours a day were least likely to catch the virus. "Touching and rubbing of the eyes with contaminated hands may be a significant route of infection," the study states. "Long term use of spectacles may prevent repeated touching and rubbing of the eyes."
The study is yet to be peer reviewed.
Study details
Risk of Corona virus disease 2019 (COVID-19) among spectacles wearing population of Northern India
Amit Kumar, Saxena Senior
Published in medRxiv on 13 February 2021
Abstract
Introduction
Severe Acute Respiratory Syndrome Corona virus-2 (SARS-CoV-2) spread mainly through respiratory droplets and contact routes. Long term use of spectacles may prevent repeated touching and rubbing of the eyes. Aim of the study is to compare the risk of COVID-19 in long term spectacles wearers with the risk in persons not using spectacles.
Objectives
To know the association between infection with SARSCoV-2 and wearing of spectacles.
Materials and methods
In this study, 304 patients of Corona virus disease 2019 (COVID-19) were selected. Their spectacles wearing behaviour was assessed through a questionnaire. Spectacles wearing behaviour of general population was obtained from older studies (for comparison). Risk of COVID-19 was calculated in long term spectacles wearers as well as in persons not using spectacles. Chi-Square test was used for statistical analysis.
Results
In this study, total 58 patients showed the behavior of using spectacles continuously during day time and always on outdoor activities. The risk of COVID-19 was found 0.48 in spectacles wearing population as compared to 1.35 in population not using spectacles. The calculated risk ratio was 0.36. The protective effectiveness of the spectacles was found statistically significant (p-value .00113).
Conclusion
The present study showed that the risk of Covid-19 was about 2-3 times less in spectacles wearing population than the population not wearing those. The nasolacrimal duct may be a route of virus transmission from conjunctival sac to the nasopharynx.
[link url="https://www.medrxiv.org/content/10.1101/2021.02.12.21249710v1.full"]medRxiv study (Open access)[/link]