A: Great question!
Most media attention around personal protective equipment has focused on the use of masks. We’re here to report: Face shields are protective too!
Face shields create a transparent rigid plastic barrier that covers the entire face from ear to ear and from forehead to the bottom of the chin (the more they cover, the better). They are attached by a head strap or headband, with no space between the forehead and the strap. The face shield physically blocks viral entry (through eyes, nose, or mouth) and reduces autoinoculation from touching one’s face.
Simulation studies indicate that face shields are very effective at preventing inhalation of cough aerosol droplets, with one estimate showing 96% protection from viral exposure within 18 inches of a cough. More broadly, a recent meta-analysis of protective gear published in the Lancet looked at 13 studies that lumped face shields and goggles together in a category called eye protection. This study showed that people wearing eye protection had a 6% risk of viral transmission whereas those not wearing eye protection had a 16% risk of viral transmission. The protective effects of face shields are likely much bigger than wearing only goggles, since face shields cover much more of the face.
We see other benefits to face shields, especially for children who may be heading back to school. Face shields are easy to wear, and their transparency allows others to see your full expressions and lip movement. It’s also a physical reminder, in fact a barrier, to avoid touching any part of your face. Further, face shields can be created at home from items readily available at craft stores. And finally, face shields can be disinfected and reused.
So back to your original question, which is better: face shield or face mask?
Our cautious response:
If you cannot social-distance and other people may not be wearing masks, wear BOTH a face mask and a face shield. Wearing a face mask will primarily help protect others from you (if you are asymptomatic or pre-symptomatic) and wearing a face shield will help protect you from others.
