PRESCRIPTION EYEGLASS COMPATIBLE Engineered speciically for people who wear glasses when they ski and ride, the Index OTG (Over-The-Glass) features a inely crafted interior with extra volume to comfortably accommodate prescription frames. Increased air volume inside the goggle keeps your vision crisp, clear and fog free. Specifications FRAME: OTG medium size adult frame LENS: Thermoformed cylindrical lens FEATURES: Over The Glasses technology (OTG) Temple cutouts for eyeglass frame arm pieces Double-layer face foam with micro-leece facing Anti-Fog coating Seamless Compatibility with all Giro helmets