US Patent 7597441 Polarized contrast enhancing sunglass lens

The invention is a polarized sunglass lens that utilizes a multiband contrast enhancer comprised of three rare-earth oxides to provide relatively high peak transmittance in portions of the red and green spectrum, relatively lower transmittance for the blue spectrum, and very low transmittance for the UV spectrum. The lens provides enhanced perception of colors, heightened contrast, and improved visual acuity. The inclusion of vanadium pentoxide in the lens provides attenuation of the UV spectrum, thus protecting the user's eyes and the internal layers and colorants from UV-induced damage. The front lens element can be either the multiband contrast enhancer or a photochromic lens element.