first of all, these are excellent goggles, worth every penny considering I paid 62 dollars for them here w/ coupons (EPIC). On the slopes, they have never fogged up. I have only lost visibility once, when they were spraying artificial snow and it caked ice on them, but that was a really rare experience. Other than that, the mountain is crystal clear w/ no snowblindness or the like. The only gripe I have is that if you're going to wear them without a helmet, the darn elastic band loosens a bit too easy and after a couple of runs its less than snug. Still, this didn't bother me enough to hurt the ski experience... its just a little unsettling to have your goggles that close to falling off your face. They are very comfortable on large faces and big noggins. Regardless, I would buy these all over again for performance and I have to admit... they're just downright sexy too.