The XL edition offers a standard size frame with enhanced lens coverage, and every millimeter of the peripheral view is optimized with High Definition Optics™ in a durable yet lightweight design that takes performance to the next level and brings style along for the ride.   Photochromic Built with Oakley HDO technology, photochromic lenses automatically adjust to changing UV light exposure while you're on the go.   Features Lightweight O Matter™ frame material with ellipse metal icon accents. Unobtainium™ earsocks and nosepads for increased comfort and performance. 8.75 base lens geometry with HDO™.   Clear To Black Iridium Photochromic Light Transmission: 23%. Light Transmission (activated): 23%. Light Conditions: Changing conditions. Contrast: Neutral. Base Lens Colour: Clear.