These are the swim goggles with tinted lenses that automatically brighten or darken in response to changing lighting conditions. The photochromatic lenses, common in sunglasses but unique in swim goggles, quickly darken in bright sunlight or harsh fluorescents but lighten in dimmer conditions or when the sun hides behind a cloud. The versatile goggles' curved lenses enhance peripheral vision, making them ideal for crowded pools or open-water races. The lenses are also treated to fight fog and block 99% of UV rays, and silicone gaskets seal out water while fitting gently over the eye sockets. Four hinged flexible joints help the goggles mold to a swimmer's face. Simply pulling on the straps tightens or loosens the fit. 6" W x 2" D. (4 1/2 oz.)