Bolle has long since been at the forefront in producing hi-tech, high-performance ski goggles. All Bolle goggles feature double spherical polycarbonate lenses which acts as a thermal barrier & ensures superior optical quality.The lenses block 100% of harmful UVA/UVB rays up to 400 nanometers. The double layer face foam means a close and comfortable fit. The unique helmet compatible strap system known as Forestay provides a precise and insulating fit with or without the helmet. The modulator lens lightens and darkens depending on how bright it is. Its conical frame shape gives superior downward and peripheral vision. The lens incorporates the Flow-Tech venting to reduce fogging and optomize the flow of air over the inside of the lens. Lens Vermilliion: Excellent in poor to mid light conditions. The rose tint increases the depth and perception and enhance shadow, helping to define your surroundings in the snow and help to relax the eye.