Wearing glasses on the ski hill can be an ambitious venture. Giant temperature changes, sweat, and snow. The Smith Knowledge Turbo Fan OTG Goggles are a cut above the rest of the over-the-glass goggles. The Turbo Fan is just that, a turbo fan. Set into the top of the frame, when activated, the turbo fan quickly moves hot damp air out of the goggles, clearing fog and keeping you skiing. Two layer face foam, articulating straps, and cutouts in the frame to accommodate glasses make these some of the best over the glasses goggles to date. Not just for people with glasses, anyone with a super sweaty dome-piece can cut through the fog with the Smith Knowledge Turbo Fan Goggles.