Episulfide composition, polymerizable composition, cured product, optical material, and lens

An episulfide composition comprising an optically active compound A,

• wherein:
• the optically active compound A comprises one disulfide bond and two episulfide rings, and
• one of the two episulfide rings is an episulfide ring 1 containing an asymmetric carbon atom C*1, and another of the two episulfide rings is an episulfide ring 2 containing an asymmetric carbon atom C*2,
• wherein the optically active compound A comprises:
• at least one of an optically active compound A-SS in which both of the asymmetric carbon atom C*1 and the asymmetric carbon atom C*2 have an S configuration, or an optically active compound A-RR in which both of the asymmetric carbon atom C*1 and the asymmetric carbon atom C*2 have an R configuration;
• and
• an optically active compound A-RS in which one of the asymmetric carbon atom C*1 and the asymmetric carbon atom C*2 has an R configuration, and another of the asymmetric carbon atoms has an S configuration;
• and
• wherein a ratio of a peak area RS of the optically active compound A-RS to a total peak area T of the optically active compound A-SS, the optically active compound A-RR and the optically active compound A-RS, as measured by high performance liquid chromatography, is from 10% by area to 70% by area.