Oakley engineering takes performance to the next level and brings style along for the ride. Flak 2.0 offers a standard size frame with enhanced lens coverage, and every millimeter of the lens is optimized with High Definition Optics® in a ruggedly durable yet lightweight design. Designed to push your limits with patented XYZ Optics® for razor sharp clarity and secure grip of Unobtanium®Features:- Click here to explore Flak 2.0- PRIZM™ is a revolutionary lens technology that fine-tunes vision for specific sports and environments. See what you've been missing. Click here to learn more about Prizm Lens Technology.- The XL edition offers enhanced lens coverage and specialized lens curvature for protection against sun, wind and impact- Unobtanium® earsocks and nosepads keep glasses in place, increasing grip despite perspiration- Patented High Definition Optics® (HDO®) provides superior optical clarity and razor-sharp vision at every angle- O-Matter™ stress-resistant frame material is both lightweight and durable for all-day comfort and protectionTechnologies:Prizm™:- Prizm™ is a revolution in lens optics built on decades of color science research. Prizm™ lenses provide unprecedented control of light transmission resulting in colors precisely tuned to maximize contrast and enhance visibility.High Definition Optics®:- High Definition Optics® (HDO®) is a collection of patented technologies that allow Oakley eyewear to meet or exceed the testing standards of the American National Standards Institute for optical clarity, visual fidelity, and impact resistance.