A Soft Touch, jet-black chassis is paired with a precisely regulated polycarbonate UV filtering system. The non-polarized Polaré lemon filter is an ultra high contrast absorptive tint that allows 86% visible light transmission, while blocking 100% of lightwaves up to 470 nm and all UVA/UVB rays. The filter is designed to absorb 40% of blue light and 70% HEV (High-Energy ultra-violet light) that can cause irritating eyestrain and fatigue. This item is final sale, no returns or exchanges allowed. For sizing over your glasses:Measure the prescription glasses straight across at their widest point and from top to bottom at their tallest point, including the frame. Both measurements need to be at or below the maximum listed for the Cocoons size. If either measurement exceeds the limit, move to a larger size. Cocoons size Size code Maximum Rx frame dimensions Stream Line S 128 mm wide × 36 mm high (5 1/16" × 1 7/16") Mini Slim MS 130 mm wide × 36 mm high (5 1/8" × 1 7/16") Slim Line M 135 mm wide × 42 mm high (5 3/8" × 1 11/16") Wide Line ML 138 mm wide × 36 mm high (5 7/16" × 1 3/8") Pilot L 139 mm wide × 50 mm high (5 1/2" × 2") Aviator XL 142 mm wide × 50 mm high (5 5/8" × 2")