Oakley Flak 2.0 Sunglasses have a standard size frame with enhanced lens coverage, and every millimetre of the lens is optimised with High Definition Optics in a ruggedly durable yet lightweight design._ PRIZM is a revolutionary lens technology that fine-tunes vision for specific sports and environments - see what you've been missing!XYZ Optics for razor sharp clarityXL edition: enhanced lens coverage and specialised lens curvature for protection against sun, wind and impactUnobtanium earsocks and nosepads keep glasses in place, increasing grip despite perspirationPatented High Definition Optics (HDO) provides superior optical clarity and razor-sharp vision at every angleO-Matter stress-resistant frame material is both lightweight and durable for all-day comfort and protection