Those who say Scott turbo fan goggles work great probably do not have prescription glasses inside them.
I've had the Scott goggles with the fan for 20 years and have given up since in warm weather the Rx glasses
inside fog quickly.
I've tried all sorts of anti fog stuff, eg cat crap, spit, no fog cloths &etc.
Helmets only make the problem worse since the restrict airflow around goggles.
To even wear the goggles at all while snowing I have to ditch the helmet & go back to a knit cap.
I've found a wide brimmed visor in a wool cap works best while snowing. Of course this doesn't work in
over the head blower powder, but realistically, I've never skied in that.
The Scott Turbo Fan goggles now sit at home collecting dust.
They'll work if/when I ever get contact lenses.