The blue light is the most harmful light in all visible light. The risk of stargardt's disease (fundus flavimaculatus) will be improved after a long-term exposure on blue light which exist not only in outdoors but also indoors such as computer screen, office lights, smart-phone screen. However, anti-blue lenses can effectively block these harmful blue lights to protect eyes and reduce the risk of stargardt's disease. Company introduction Changxing, optical, glasses, factory, has, established, more, than, 10, years, in, danyang, city, jangsu, province, china., therefore, , our, factory, can, provide, better, quality, lenses, with, competitive, price., our, factory, has, two, product, lines, to, produce, normal, and, function, lenses, which, contain, cr39, 1.499, lenses, , 1.56, , 1.61, , 1.67, high, index, lenses, , sunglasses, lenses, , blocker, blue, lenses, , progressive, lenses, , and, photochromic, lenses, with, more, than, 10, 000, pairs, per, day. Types of products, Cr-39, 1.499 Photochromic, lens 1.61/1.67 high index lens 1.56 tinted sunglasses lenses 1.56, middle, index, lenses, Semi-finished, lenses Progressive lenses Blocker blue lenses Uv400 lenses 1) standard white envelopes for free 2) your design with your logo, need extra charge 3) cartons: standard cartons: 50cm*42cm*38cm (every carton can include around 500 pairs lens, 21kg/ per carton)