Subcutaneous injection of 20 μmol sodium selenite/kg body weight into 9-day-old male or female Sprague-Dawley rats caused the appearance of large nuclear cataracts within 72hr. Lens glutathione was depressed to 40% of normal after 24 hr, 50% of normal at 48 hr, and was still depressed to 70% of normal through 12 days post-injection. The lens NADPH pool was only 70% of normal 24 hr after selenite administration but was normal at 72 hr. Lens protein sulfhydryl content was also diminished by 12% when measured at 6 days post-injection and a reduced rate of lens growth was apparent by 12 days after treatment. Maximum lens selenium accumulation was observed at 24 hr post-injection and amounted to a tripling of the normal level of this element. The results indicate a direct and sustained interference of selenium with glutathione metabolism. The model should be useful for the further study of the role of glutathione in normal and abnormal lens metabolism.