Bolle has taken its cue from the oversized, spherical lens goggle designs that have become all the rage with its Emperor Goggle. As its name suggests, the goggle is king of Bolle's line in terms of size, designed to suit larger faces and offer a maximum field of vision. In addition to offering the widest field of vision of any of Bolle's goggles, the goggle is packed with vision and comfort enhancing technology. The goggles' double lens construction, anti fog coating on the inner lens, and Flow Tech vents on the frame all work together to control airflow, temperature, and condensation to prevent fogging, while the Equilizer Vent in the lens stabilizes pressure between the front and back lens to prevent optical distortion and fogging at varying altitudes. The goggles provide 100% UV protection to guard eyes against harmful rays that reflect off snow, and the category 2 Vermilion and Aurora lens tint options increase contrasts to provide excellent optical clarity in conditions that range from cloudy to sunny. Bolle's Sports Optical System S. O. S. prescription adapter fits inside the frame if you are interested in an integrated prescription lens option. The goggles' triple layer, multi density face foam is firm yet cushy, and along with the soft, moisture wicking micro fleece backing, provides long wearing comfort as well as creates a secure seal. The silicon strap enhances grip to keeps the strap secured over a helmet.