Foster Grant Multi-Focus James Black Crystal reading glasses are simple and casual. This lightweight pair has a classic acetate composition with a combination of a transparent interior and glossy black exterior. Multi-Focus Reading glasses utilize three different strength prescriptions in one pair of reading glasses. The bottom of the lens features the selected power for reading. The middle of the lens features a prescription slightly less than normal reading strength designed for computer use. The top of the lens features half the strength of the reading power for interacting with others.