Serengeti Medium Aviator 7190 Shiny Gunmetal Polarized 555nm Sunglasses Serengeti Aviator Medium sunglasses have scratch/impact-resistant lenses that guarantee optical clarity, 100% UV protection, & reduce eye strain & fatigue. The Spectral Control® Lens System reduces glare. All Serengeti sunglasses are designed with Photochromic lens technology making each lens adjust to light changes in the environment.