Smith Optics Backdrop Polarchromic Sunglasses feature a sleek design & style, while comfortably maximizing colors & depth perception. Backdrop Polarchromic Sunglasses are both polarized to eliminate glare & photochromic to automatically adjust lens tint in response to changing light conditions. These adjustments to varying light levels make the Backdrop the ideal pair of sunglasses for any outdoor activity at any hour of the day.