This review attempts to interpret the basic science and more esoteric aspects of diseases associated with cataract, in the context of practical management and diagnostic implications. In the past year, the large epidemiologic Beaver Dam Eye Study has dismissed many putative relationships between cataract and cardiovascular risk factors. However, glycated hemoglobin and high density lipoprotein cholesterol levels still have an association. Cataract continues to be associated with a number of systemic diseases and syndromes such as atherosclerosis, diabetes mellitus, atopy, juvenile rheumatoid arthritis, Marfan's syndrome, and the Cronkhite-Canada syndrome. The unifying role of oxidative stress in the formation of these, as well as iatrogenically induced laser cataracts, is presented, together with a biochemical update on the pathogenesis. Finally, to bridge the gap between the basic science and clinical significance, recent controversial and practical management issues have been highlighted.