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.With High Definition Optics® in a ruggedly durable yet comfortably lightweight design, this semi-rimless slice of Oakley engineering takes performance to the next level and brings style along for the ride.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.POLARIZED®Improving safety, comfort and performance, Oakley HDPolarized lenses filter out 99% of reflected glare without the haze and optical distortion that can come with polarized lenses made with conventional manufacturing techniques.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.