| 摘要 |
Provided is optical glass that does not contain lead, which is an environmental pollutant. The optical glass is ideal for the transmission of light even after being exposed to X-rays, and has a high refractive index. The optical glass comprises, by mass% in terms of oxide versus the glass total mass, 1.0% to 60.0% of an SiO2 component, and one or more selected from the group consisting of an La2O3 component, ZrO2 component, TiO2 component, Nb2O5 component, and Ta2O5 as essential components. The optical glass has a refractive index (nd) of 1.50 or greater, and has an intensity recovery rate of 45% or greater when exposed to X-rays at a dose of 2.5 Gy and then to a xenon lamp for 11 hours. |
