This is the Multi-View Model 77, a single vision reading glass available from a +1.0 up to a +2.0 and is sized for the average unisex head. Available in a crystal, tortoise/clear or black. The single Vision Poly Aspheric lens is the latest in reading lens technology: Impact Resistant, Thin Light Weight, scratch resistant and includes 100% UV protection. A Poly Aspheric lens really makes a differance, especially in higher powers, since the lens will be thinner and thus, more lightwieght. There is noticably less magnification of your eye and the wearer gets better peripheral vision. Style 78 is made from a high end, optical quality acetate material and has spring hinged temples. Includes a clam shell design hard protective case. Style 77 is sized for an average unisex head size. Here's the optical sizing scoop on Style 77: Lens: 51mm, Bridge: 17mm, or in inches, it's 5 1/8 wide and 1 3/8 deep.