So far, no scientific studies have been conducted to determine if a face shield is more beneficial than a mask, she said.

“We’ve never before cared about comparing face shields or masks for what we call source control, which is what we’re using them for now — protecting other people from you,” McGeer told The Current guest host Mark Kelley.   

Here is part of their conversation.

It’s not just really a question of style. People are thinking about it as a question of safety. So where do we land on that, at least with conventional wisdom, if not science?

The fact that there’s not definitive science looking at infection rates doesn’t mean there’s not a lot of science behind it that you can look at and think about how it works. 

The bottom line is it probably doesn’t matter. 

I think if you canvassed experts, most of us would say that we have better data supporting masks. There’s some reasons to think that masks might be a little better for source control — with the emphasis on little. 

So I really think it doesn’t matter whether you’re wearing a face shield or a mask. Either one of them will do well. 

People are trying to make up their own minds as they go along in this pandemic and how best to protect themselves, how best to protect others. 

Kristjan Heyden, a hair stylist and creative director at Civello Hair Salons in Toronto, says he is wearing both shield and mask at the same time. What do you think about that? Does wearing a face shield and a mask actually provide extra protection? 

Probably not. Conventional wisdom does not tell you that two is better than none. It feels that way, no question, but that’s not evidence. 

Remember that mostly we’re wearing masks or face shields to protect other people from us. The key issue is what happens to the air that’s coming out of your nose and your mouth. And whether you’re wearing a face shield …  or mask, as long as your nose and mouth are covered, then you’re fine. 

WATCH | Clinical psychologist examines the refusal by some to wear masks:

Here’s an exception. One reason why face screens and masks together might be a problem is that …  when you wear anything on your face, [if] you raise your hands to your face more often because it’s uncomfortable, because you have to adjust it, whatever, then that’s bad. 

One of the things we tend to forget is as long as your face is covered, you’re OK. But your hands are a problem too … because you can also transmit [COVID-19]  with your hands. 

I’ve heard this point, and I want to raise it with you as well, is that masks hinder communication. Especially for those who are hearing impaired. We don’t tend to realize how much lip reading we actually do, even if our hearing is perfectly good, because we tend to look at the lips.

Does that make the face shield more advantageous for people who are concerned about getting their message across? 

There is actually evidence about the intelligibility of masks and its from the U.S. Army, interestingly enough. [It] says that, yes, wearing a mask does impede communication, but not enough to impede understanding from most people.

So as long as people are not hard of hearing that the difference is not significant, you lose a couple of words, but you don’t lose the sense. 

For people who are hard of hearing, that is different. And there are circumstances in which face shields for that reason might be better. 

Now restaurants are reopening, we’re seeing servers also having to make these decisions, whether they wear one or the other. 

Kelly Jordan-Hamilton at Viaggio Hospitality in Vancouver says that at their restaurants, they’ve found servers prefer to wear them because they’re just easier. What about you personally? Do you have a preference?

It’s interesting. I find a mask more comfortable than the face shield. But when we worked with health-care workers at Sinai, looking at what people prefer, it really [came down] to personal preference a lot of the time. 

Some people would rather wear a face shield, some find shields a bit confining if they’re shaped around your face and would prefer to wear masks. Some people don’t like the pull of a mask behind their ears. So there’s all sorts of reasons for preferring one or the other.

There’s a real advantage to having choice. Sometimes just having a small element of that in your life, something to have control over, makes you feel better about life in general. 

Written by Adam Jacobson. Produced by Arianne Robinson. Q&A has been edited for length and clarity.