The Line Miner XM is a medium sized goggles that uses a streamlined frame design and a cylindrical lens that sits close to the face, creating an exceptional field of view. Packed full of features it offers skiers and snowboarders the protection and comfort they need from their goggles to enjoy endless days in the mountains. Uses Oakleys Prizm lens technology which has been specifically engineered to enhance visibility and contrast.The Dual lens has an F3 Anti-fog coating to prevent moisture build-up and keep your vision clear.The frame has discreet notches allowing compatibility with most prescription eyewear. Triple-layer polar fleece foam creates a solid yet comfortable/dry fit. LensPrizm Rose is best suited for snowy and cloudy days with the rose tint increasing depth perception and contrast. Prizm technology blocks specific wavelengths of light whilst boosting others to provide maximum contrast and enhanced visibility. This greater clarity results in reduced reaction times and increased performance over a wide range of light conditions.Visual Light Transmission, VLT, refers to the amount of light that penetrates a lens. A low percentage means less light passes through and a higher percentage lets an increased amount of light through. A lens with a lower VLT rating is better for bright conditions, where as one with a higher VLT is more suited for overcast and snowy days.