I have a beard - about the only thing I can wear that produces no glasses-fogging in the cold is a P100 respirator. It has an exhaust valve so it was not protective to folks around me until I McGuivered air filter foam over it. The key seems to be an elastomer ‘flap’ against my face (if I put my hand over the exhaust I can make my ears pop).

There are silicone skirted masks out there with no valves. So far, the Castle Grade G9 seems about the best, but I've seen pictures of one developed at MIT/Brigham's which I hope becomes available soon. In both cases, you get a better face seal and there's less medical waste being produced. As best as I can tell, these are n95. use the same three layers with the middle one an electrostatic blown-fiber layer (first developed by 3M).

Also: thank you so much for helping MRSA patients.