Well, Im on my second pair of ski goggles and they fogged up to the point where I had to take them off during my commute home. This is the second pair that were stated on the box that they were fog proof. Not sure if its a blend of fog and moisture from sweating, but Ive been on the slopes and have sweated just as bad. This sucks, do I have to blow 100 bucks on a pair that has the high tech venting? I paid 45 for this last pair!