I have to pinch the mask a little so that my breath don't fog the damned glasses up. Real pain in the ass... And my boss even talked about this new desease isn't one that air borne, but rather through touches. So masks are useless. The thing to do is to keep both hands clean, sterilized everywhere.
Was wearing it for a couple hours during medical visit to hospital for my mom, but decided not wear it again because of the same reason, and some - basically being a snot factory at that time, it sticks on the mask and it feels uncomfortable. And the fogging hinders my vision when i drive.