Types of Lenses
In contrast to anti-reflective coatings, which are very clear, mirror coatings (also called flash coatings) are bold statements of color. Just as the name implies, a mirror coating is highly reflective. The mirrored sunglasses associated with state troopers are one example of a flash coating.
The technology has advanced, however, so that today's choices include colors of the rainbow as well as silver, gold and copper metallic mirror coatings. Hot pink, blue — almost any color is available.
Mirror coatings are purely cosmetic: the wearer perceives no difference in vision regardless of what color the coating is. Only those looking at the person wearing the glasses can see the color of the mirror coating. Mirror coatings are generally applied over sunglass-dark lenses. Obviously, a highly reflective flash coating prevents others from seeing the eyes of the wearer.