Imagine hitting a dangerous curve at 186,000 miles per second. With ordinary lenses, thats what light has to deal with, and the rays skid off in directions that cause visual distortion. So when Oakley made a frame with this much curvature, they used HIGH DEFINITION OPTICS (HDO) to achieve the best clarity under the sun. All that contouring maximizes peripheral vision and side protection against sun, wind and impact. Lightweight C-5 alloy is combined with custom-engineered spring hinges to optimize comfort, and 3-D digital sculpturing puts the look in a category of its own. The open-edge lenses offer an unobstructed downward view while filtering out 100% of all UV. Their renowned Three-Point Fit keeps the lenses in precise optical alignment. UNOBTAINIUM stem sleeves maintain a supple grip, and sweat only makes them grip better.