Solar Bat Chevrolet sunglasses are GM Officially Licensed Products and made in the USA. The line includes five different frame styles with two of the styles also available in prescription. The lenses have PNVXD optics designed by owner and optometrist, Dr. Gary Nesty, in 2010. PNVXD optics stands for Prescribed Natural Vision with Extra Definition. Dr. Nesty states, “I designed front and back surface curve variations with lens thickness changes to maximize visual performance no matter what the direction of gaze. This means that the PNVXD optics will actually improve visual acuity, depth perception and peripheral vision in glare situations. I called on my knowledge of optics, as a Doctor of Optometry, to design the ultimate lens for visual performance in the outdoors.” PNVXD lenses also feature the maximum in polarization and filter all wavelengths of UV. Lenses have a double thickness scratch coating on the front and back surfaces for durability. The polarizing film is not glued on the front surface but encapsulated within the molded PNVXD lens. Lenses are available in gray or amber polarized tints. See the full line of Solar Bat Chevrolet sunglasses at www.solarbat.com or call for a catalog at 800-761-8228.