Photoinduced changes in the optical absorption and dielectric properties of PbMoO4 and Pb2MoO5 crystals are considered.Differences in the manifestation of the photochromic effect in both crystals are associated with differences in their crystal structure.It is assumed that the photodielectric effect in the PbMoO4 and Pb2MoO5 crystals is due to the presence of the same anionic complexes.The nature of the structural defects in the crystal lattice and their transformation under the heat treatment of PbMoO4 and Pb2MoO5 crystals in various atmospheres and ultraviolet irradiation was analyzed.topics