... optical lens 1. various types: cr 39 1.499, 1.56, 1.61, 1.67,1.523 2.uncoated, HC, HMC 3 ... .Diameter: 70, 65,60, 55 cr-39 optical lens1. various types: ... detailsBesides, we can supply you the lens as following: 1. GLASS LENS (index 1.523, 1.70 ... 3. BIFOCAL LENS (glasses & CR-39. round-top bifocal, flat-top bifocal, blended bifocal and curve bifocal lens)4. PROGRESSIVE LENS. optical lens ...