I think the OTG Turbo Fan was going to turn out to be slightly better than conventional Smith goggles in preventing fogging of my glasses. I'm not sure because on the first day I had the new Turbos, I was skiing in the trees at Winter Park, with my new Turbos up on my helmet because it was a blue bird day, and I had my sunglasses on. I heard a branch hit my helmet, but didn't think much about it, until we were at the car and I couldn't find my new Turbos. Then I remembered the branch, and realized the Turbos were up in the trees to be found by some hiker this summer.