Photosensitive cataractogens, chlorpromazine and methoxypsoralen, cause DNA repair synthesis in lens epithelial cells.

Autoradiographic techniques showed that photoactivation of methoxypsoralen opr chlorpomazine caused diffuse nuclear labeling of lens epithelial cells by thymidine. Chlorpromazine and light also induced thymidine incorporation into lymphocytes, whereas light or drug alone did not cause unscheduled DNA synthesis.