This is the optical quality, single vision MV Optical Model 1 with CR39 optical reading lenses. The classic preppy rounded frame is available in a Brown, Black, Pewter or Tortoise finish that looks great on a wide variety of head shapes. The temples have integrated spring hinges assuring a comfortable fit. Model 1, by the experts at Multi-View Optical is a very high end, optical quality acetate frame sized for an average (unisex) head size. These single vision CR39 acrylic lens reading glasses are available in any power from +1.0 up to a +2.0. A CR39 optical lens is the latest in reading lens technology: Impact Resistant, Thin Light Weight, scratch resistant and includes 100% UV protection. Style 1 has a smooth acetate finish with spring hinged temples. Available in black or brown. Includes a clam shell design hard protective case.. Style 1 is sized for an average head size. Here's the optical sizing scoop on Style 1: Lens: 48mm, Bridge: 18mm, Temple: 140mm