minimum environmental impact and maximum field of vision. with an exceptionally wide field of vision, bio-based frame materials and easily replaceable lenses, the zonula combines sustainable features with outstanding ease of use. the holders on the frame make it easier to handle the goggles and make it easy to change the lenses. the frame and strap are made from 47 % bio-based materials to minimise environmental impact. clarity lenses, developed in collaboration with carl zeiss, ensure optimum visibility on the snow in all conditions.clarity define no mirror lensclarity lens technology filters out specific areas of the colour spectrum, allowing for precise and clear vision even in changeable weather conditions. transmittance of visible light: 22 %