... Bifocal Lens Index: 1.499 1.56 1.60 Diameter: 70/28 75/28 80/28 70 ... the largest lens manufacturer in China, Wan Xin Optical is the only Chinese listed company. In 2009, ... we have been supplying lenses to many world-known optical companies.We produce single vision, bifocal, progressive, photochromic ... with index of 1.499, 1.56, 1.60, 1.67, both in finished and semi-finished. ... Lens 1.499 1.56 1.60