A curable composition which comprises a carbonate-based polymerizable monomer represented by the following formula, other polymerizable monomers and a photochromic compound, can be used even under high-temperature and high-humidity conditions without any problems and provides a cured product having excellent photochromic properties. wherein A and A′ are each a linear or branched alkylene group having 2 to 15 carbon atoms, “a” is an average value of 1 to 20, when there are a plurality of A's, A's may be the same or different, R1 is a hydrogen atom or methyl group, and R2 is a (meth)acryloyloxy group or hydroxyl group.