The Oakley SI M Frame® surpasses ANSI Z87.1 Industrial Standards for high-mass and high-velocity impact protection  Incorporating HIGH DEFINITION OPTICS® (HDO®) technology, lens geometry comes in five interchangeable lens shapes.  All lenses are made of pure Plutonite®, a proprietary material that offers the highest level of optical clarity available in eyewear. You get razor-sharp clarity at all angles of view, which maximizes peripheral vision and protection against sun, wind and side impact.

Features

• Shatterproof, scratch-resistant Plutonite® polycarbonate lenses can be replaced with other colors and shapes, sold separately
• Polar Ellipsoid™ lens shape eliminates distortion
• Hammerfang™ ear stems provide a 3-point fit to comfortably accommodate various head sizes
• Patented hydrophilic silicone earsocks and nosepieces become tacky when wet, so they won't slip down when you perspire