This is sculpture mixed with science, and theres a reason behind every curve. The side-to-side contour of a lens can make or break peripheral vision. The Scalpel has a full 8.75 base curvature to open your range of view. That much of a contour leads to optical distortion in ordinary sunglasses but this is engineered with XYZ Optics to maintain critical clarity along the entire lens curve. Youll have added protection against sun, wind and side impact. As a matter of fact, this design meets all ANSI Z87.1 basic impact standards, and the pure Plutonite lenses filter out 100% of all UV. The smooth sculptural contours are made of durable, lightweight O Matter, plus the stem sleeves got some special attention. Note how they wrap the ends and continue along the underside. Theyre made of Unobtainium, a material that increases grip with sweat, and theyre part of a Three-Point Fit that maintains comfort all day while holding the lenses in precise optical alignment.