MIT Medical answers your COVID-19 questions. Got a question about COVID-19? Send it to us at CovidQ@mit.edu, and we’ll do our best to provide an answer.
I'm wondering about the efficacy of wearing a face shield rather than a face mask. I ask because I wear glasses with trifocal lenses, and they don’t sit in the proper location when I’m wearing a mask. However, I believe that they would stay in place with a face shield, and I’d like to suggest that option to my manager. In the return-to-work planning for MIT, is the Institute is considering giving staff the option of wearing face shields rather than mouth/nose masks?
Thank you for an interesting question. Masks and glasses can be a cumbersome combination, and I’m sure you are not the only one wondering if there’s an alternative to the face mask. Unfortunately, face shields are not an adequate substitute.
We know that the virus spreads primarily from person to person through respiratory droplets that are produced when we talk, sing, shout, or even breathe. We know that as many as 40 percent of people who are infected with the virus never develop noticeable symptoms but are still capable of spreading the virus. We also know that individuals who do become ill with COVID-19 are at their most contagious just before they develop symptoms.
Therefore, we wear masks to protect not only ourselves but also each other. If I am infected, my mask will capture any large respiratory droplets I produce before they are expelled into the air, thereby preventing me from unknowingly infecting people around me. A face shield, by nature of its design, would be more likely to allow these droplets to escape.
When it comes to your personal dilemma, you might try experimenting with different types of face masks to see if you can find one that works with your glasses. Many people who wear glasses recommend choosing a mask with a wire insert that allows it to be molded to the nose just below the spot where one’s glasses are resting. This type of mask should allow you to keep your glasses in place with the beneficial side effect of reducing fogging. Many such masks are commercially available, but if you’re handy, you might want to check out this DYI pattern and video instructions.
Of course, social distancing is the main strategy for preventing person-to-person transmission of the virus. So, even once you’re back on campus, there will be no need for you to wear a mask at times when your coworkers or others are more than six feet away. If the nature of your job allows, you might choose to wear a face shield while keeping a mask around your neck, ready to be pulled up and deployed when needed — in other words, at any time that you can’t maintain an adequate social distance.