High-refractive-index optical glasses having refractive indexes of from 1.84 - 1.87 and Abbe numbers of from 30 - 33

摘要

A novel optical glass having refractive indexes of from 1.84-1.87 and Abbe numbers of from 30-33, which can preferably be used as reading area fusion glass for spectacles, comprises (in % by weight): SiO2 7-11, B2O3 11-15, Al2O3 0-3; alkali metal oxide 1.5-5, alkaline earth metal oxide and zinc oxide 6-20; La2O3 20-34, Y2O3 0-7, Gd2O3 0-7, ZrO2 4-8, TiO2 4-12, PbO 0-20, Nb2O5 5-12, WO3 0-4, Ta2O5 0-6.