| abstract |
A fixed tint, photochromic glasses and sunglass lenses produced therefrom. The glasses have R 2 O—Al 2 O 3 —B 2 O 3 —SiO 2 base compositions, contain silver chloride and bromide contents as photochromic constituents and 0.27-0.38% and 0.035-0.060%, both by weight percent, as glass colorants, the NiO:Co 3 O 4 ratio being at least 6:1. |