Epidemiology of age-related cataract

To investigate the aetiology of cataract, it is necessary to measure both t he type and severity of lens opacities, as well as the dose and duration of exposure to the putative risk factor. Great advances have been made in rec ent years in our ability to measure cataract and some putative risk factors . Our current understanding of the aetiology of cataract shows that by far the greatest effect is seen with increasing 'age'. However, exposure to ult raviolet-B (UV-B) radiation, use of dietary antioxidant vitamins and the pr esence of diabetes, the occurrence of dehydration and severe diarrhoea and the use of therapeutic drugs such as steroids, and recreational drugs such as nicotine and alcohol, may be important risk factors. Until the results o f the current studies of the effectiveness of antioxidant vitamin supplemen ts become available, the only effective protective interventions to reduce the risk of cataract seem to be to reduce ocular exposure to W-B radiation and to stop smoking.