Namaha For Life Photochromic glasses when exposed to ultraviolet (UV) rays as in direct sunlight, undergo a structural change that causes them to absorb a significant percentage of the visible light, i.e., they darken. The reversible darkening of glasses enables one to use these glasses in the sun and it protects the eyes from direct UV. These lenses darken when exposed to ultraviolet light of the intensity present in sunlight, but not in artificial light. These glasses are of zero power and anyone can use it. It comes with a Box and a Cleaning cloth. These sunglasses are assorted color frames.