The present invention can provide a composition for optical members, which contains (a) a compound having one or more of any group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group and one or more β-epithiopropyl groups in a molecule. In a preferable embodiment of the present invention, the composition for optical members further contains at least one compound selected from (b) a compound having one or more β-epithiopropyl groups in a molecule while having no polymerizable unsaturated bond group, (c) an inorganic compound having a sulfur atom and/or a selenium atom, (d) a compound having one or more thiol groups in a molecule, (e) a compound having one or more amino groups in a molecule while having no heterocyclic ring, and (f) a compound having one or more of at least one group selected from the group consisting of a vinyl group, an acryloyl group, a methacryloyl group and an allyl group in a molecule.