Bolle Helix Sunglass Replacement Lenses, TNS Fire B-clear lenses enhance your ability to see what's coming at you, and who you've left behind Ultra-lightweight trivex lens material Optics Control System is an interchangeable lens System that allows you to swap out the lenses for different lighting conditions Dual-sided hydrophobic/oleophobic coatings Carboglas Coating gives an armor shell from scratches and abrasions