70s Ray-Ban B&L Timberline Ambermatic Sunglasses L9712 Authentic excellent condition vintage Ray-Ban Bausch & Lomb USA Timberline sport sunglasses circa 1970’s. Made in USA. Unisex. Comes with (newer)Rayban case. Retro and downright groovy acetate frame featuring three layers of coordinating hues: tan, white, and navy blue. These mineral glass lenses are brown(B-15) and are ambermatic(definition below). Features the Rayban logo in raised metal relief on the back of each temple, a laser etched BL on the outer part of each lens, "B&L Ray-ban USA" printed on one inner temple, and "Timberline" on the other. Ambermatic lenses are made of a unique light-sensing glass that self-adjusts color and density for varying light and weather conditions. Color changes from haze-cutting amber under overcast skies to glare-blocking brown under warm, sunny conditions or dark gray under cold sunny conditions. On cloudy, marginally bright days, they are lighter brown - just right for the light.