The ESS CDI Polarized Mirrored Blue Replacement Lens are 2.2mm polycarbonate replacement lenses for the CDI sunglass. These polarized lenses reduce glare and eye strain, in addition to providing 100 percent UVA/UVB protection. CDI replacement lenses are also available in Clear, Smoke Gray, Hi-Def Yellow, Hi-Def Bronze, Mirrored Copper, Mirrored Gray, Mirrored Silver and Mirrored Gray Polarized. The CDI’s Lateral Exchange System allows quick lens interchange. Important Note: ESS polarized lenses do not offer the same level of impact protection as non-polarized lenses. Although these lenses exceed ANSI Z87.1 requirements and are thus considered compliant with U.S. Federal OSHA, they do not meet the same MIL SPEC impact tests that non-polarized CDI sunglasses lenses do. Polarized products WILL NOT protect against all impacts nor will they protect against all chemical splashes.