Introduction In 1952, Howard1and von Sallmann2reported a technique for the flat preparation of the lens epithelium. This technique simplified the microscopic study of this monocellular layer. In addition, von Sallmann quantitated the number of mitotic figures present in the lens epithelium of rabbits and found changes in the number of mitotic cells per lens epithelium in irradiated rabbits.2 Subsequently, changes in mitotic counts in the lens epithelium were reported after x-ray irradiation in other animal species3and after the administration of alloxan,4myleran,5iodoacetate,17or galactose,5all known cataractogenic agents. Further, mitotic counts have been useful in evaluating lens culture media6,7and the effects of cataractogenic dyes in vitro.8 The mitotic cycles of cultured lenses were calculated by Constant7by adding colchicine (which arrests mitosis at metaphase) to the incubating media. In a previous study,9systemic