Optical glass

An optical glass having optical constants of a refractive index (nd) exceeding 1.85 and an Abbe number (νd) of 40 or over and comprising, in mass % calculated on oxide basis, 3-8% SiO2, 5-19.5% B2O3, 15-50% La2O3, 0.1-25% Gd2O3, exceeding 10% up to 25% Ta2O5, 1.5-6% WO3, 0-1% TiO2, 0.1 or over ZnO and Li2O, said optical glass being substantially free of Pb and As, and having glass transition temperature (Tg) of 630° C. or below, wherein the total amount of La2O3, Gd2O3, Yb2O3, ZrO2, Ta2O5, Nb2O5 and WO3 is 78% or below, log η which is logarithm of viscosity η at liquidus temperature is 0.8 or over, and liquidus temperature is 1100° C. or below.