a classic from anon. the anon helix 2.0 goggle with perceive lenses has the wide field of view and flat design of a cylindrical lens for the best optical performance. the full-length vents and anti-fog treatment ensure clear vision on the mountain.these goggles come with the perceive sun red lens, or the perceive varible green lens and an amber lens as a bonus lens. perceive sun red lensthe perceive sun red lenses are suitable for very sunny days and slightly cloudy days. perceive lenses provide high contrast to better see the terrain. transmittance of visible light: 14 %perceive variable green lensthe perceive sun red lenses are suitable for changeable days. perceive lenses provide high contrast to better see the terrain. transmittance of visible light: 22 %