Glasses and fask mask is a problem period.

I know first hand. I have tried anti-fog and even left my glasses out over night in the elements so there wouldn' t be cold to hot transition. A face mask just traps too much air. I find that I have to slit my face mask a bit at the bottom and breath out the bottom of the mask to keep them from fogging. Really a pain but face painting does work.

I find that if I leave my binoculars out in the weather they don' t fog up other than the first time I take them out. Leave window cracked a bit or put them in bed of truck or the toolbox keeps the temperature close to the outside air and has lead me to fewer fog ups. Hope it helps