The Oakley Flak 2.0 XL Replacement Lenses feature the unbeatable clarity, impact resistance and 100% UV filtering of Oakley's HIGH DEFINITION OPTICS® (HDO®). Oakley Flak 2.0 XL Replacement Lenses Features Clarity: Conventional lenses can magnify images. HDO® precision gives less distorted vision across the entire field of view. Refraction: With regular lenses, objects aren’t really where you see them. HDO® offers a truer visual image so your brain won’t have to work overtime. UV Protection: All Oakley lenses block 100% of UVA, UVB & UVC rays and harmful blue light up to 400 nm.