Optical material composition and optical material

A composition for optical materials, consisting of:

• an episulfide compound (A) in an amount of 65 to 90 parts by mass with respect to 100 parts by mass of the composition,
• a polythiol compound (B) in an amount of 10 to 35 parts by mass with respect to 100 parts by mass of the composition,
• a photochromic compound (C) in an amount of 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the composition, and
• sulfur as an optional component, an optional polymerization catalyst and an optional curing catalyst;
• wherein the photochromic compound (C) is selected from the group consisting of a spiropyran compound, a spirooxazine compound, a spiroperimidine compound, a benzopyran compound, a fulgide compound, a naphthopyran compound, a diarylethene compound, and an azobenzene compound.