When premier athletes like Lance Armstrong look for precision optics and protection, they look to the Oakley M Frame Heater Sunglasses. These sport sunglasses are for athletes who take their sports seriously. Oakley used true Polaric Ellipsoid geometry to contour the Heaters single lens in three directions for optimal protection against sun, wind, and side impact. XYZ optics offer distortion-free vision and dark lenses make these Oakleys ideal for very bright conditions. Precise hinges and a sloped shape create a tight fit across the brow for not-going-to-come-off comfort, and give you a huge field of vision with excellent peripheral protection. The Heater Sunglasses are the largest M Frames that Oakley makes, and are best suited for large faces and for those who need maximum coverage.