To get the best possible performance and safety, you need to match your optics to your environment. Trouble is, no two environments are exactly the same, and light conditions change throughout the day. Thats why this pair of sunglasses comes with three interchangeable lens sets, and all are engineered with patented performance. Oakleys High Definition Optics (HDO) hones vision with razor sharpness, and with XYZ Optics, the lens clarity extends to the far edge of contours that maximize peripheral view and side protection. UV filtering is 100%, and performance meets ANSI Z87.1 standards for optical clarity and impact resistance. The frame is made of durable O Matter with Unobtainium components that increase grip with sweat and take comfort to a new level. The G20 lenses are designed to enhance visual contrast and improve depth perception in average sun brightness. The Persimmon lenses do the same but are engineered for lower light conditions so youll be able to keep up with the suns moods. When precise color recognition is essential, switch to the Grey lenses theyre made for a wide range of average sun brightness. For average sun brightness, use the Bronze lenses to improve depth perception. The increased visual contrast makes features in your environment pop with clarity. For low light, a set of Clear lenses are included so youll have unrivaled impact protection plus UV filtering for gray days that still let ultraviolet rays through the clouds.