DESC: Frame Type: Square Classic, Frame Material: Nylon, Lens Type: Glass Glass, Lens Colors:SKILYNX LENS: Blocks out nearly all violet and blue light. More of the Yellow-Orange-Red end of the spectrum is allowed to pass though enhancing contrast and depth perception. Great for skiing, boating or fishing. Brown based in color Allows 14% of visible light transmission. PX-2000 LENS: A more evenly balanced transmission of light that allows a bit of violet and blue light though for color rendition. Brown based lens Anti Reflective coated 14%. Visible light transmission. ?Limted supply instock hurry