Cataracts removed intracapsularly by cryoprobe technique from human diabetics were analyzed for sugars and polyols by gas liquid chromatography. The contents of sorbitol and fructose of lenses followed blood glucose levels at least up to 250 mg/dl. Studies indicate that human lens is capable of synthesizing substantial amounts of polyol pathway metabolites given exposure to high glucose levels such as are prevalent in diabetes. The synthesis of sorbitol was found to be susceptible to quercitrin, an inhibitor of aldose reductase. The implications of these findings in the formation of cataracts in diabetic individuals have been discussed.