1.71 lens Full name 1.71 refractive index lens, with high refractive index, high transmittance, high Abbe number characteristics, in the case of the same myopia degree, can significantly reduce the thickness of the lens, reduce the quality of the lens, at the same time, make the lens more pure and bright, not easy to disperse rainbow grain. It is found that adding cyclic sulfide resin into the lens material can improve the refractive index of the lens, but too much cyclic sulfide resin will lead to the reduction of light transmittance and material cracking. By precisely controlling the content of ring sulphur resin in 1.71KR resin, the 1.71 lens achieves high refractive index and abbe number while ensuring good light transmittance, low dispersion and clearer vision.