The Best Anti Fog is found at Dive Shops. I get mine from the Scuba shop.
Just make sure to tell them its for a plastic lens. The stuff for gas is too strong.
I have several masks. Priced from 25 to 85 The anti fog from the scuba shops make them all work great. These masks are worn by people from 10 to 50 years of age.
They test out find.