This has been my usual appearance working in attics and crawl spaces. At age 75, I need the glasses for acceptable vision, and value them as protection. I have been diligent with lungs protection. There is little added effort in breathing through the respirator.
Look inside a 3M Model 7502 half-mask respirator. Soft silicone comfortably conforms to my face. OSHA requires professional fitting, but that is simply with selection among three offered sizes, good-enough. Round silicone flappers (check valves) move inward with inhalation and close with exhalation. A rectangular flapper hinges outward with exhalation and block flow with inhalation. Simpler or older respirators may have a more-resistive round inhalation check at the front.
I paid $15 in 2009 for required "fitting" and OSHA training. I wear a Medium, of course. Please see much more about the fitting in a 3M training video for the less-comfortable 6000-series respirators.
We in USA are not strongly guided to protect ourselves against coronavirus. Wear an N95 paper face mask or a surgical mask, if you think you are sick and should protect others, and if you can find one,
At March 25, 2020 I am resolved to do needful shopping and other needed self-care, only when wearing my respirator. I have prepared the two that I own, one new and one routinely restored as-new with careful soap-and-water scrubbing. With the second respirator, both I and my partner may escape confinement, protected.
I know that my respirators are precious. All elements are sold-out, unavailable at Amazon or anywhere else. I must preserve them, safe, for many months. Therefore with rubber bands, attach throw-away covers of facial tissue. Gain a third set of 2091 filters by putting my dirty set through a soapy wash cycle with laundry. They come out dry and with intact structure. Know then that the two new sets of 2091 filters are ample for months of usage, laundered perhaps weekly.
A small square of paper towel will do much good toward protection of others. A cloth over my mouth instead of this would interfere with the respirator seal and surely is not a better idea.
Among things listed as beneficial these days, let's add frequent well-soaped laundry. Let that apply to hospitals and group homes too. I don't see the point in throw-away plastic or paper garb.