Inter-ethnic risk ratios for different types of cataract

Patients at Moorfields Eye Hospital were divided according to five broad geographical areas of origin in four continents, and classified according as they had cortical, nuclear, posterior subcapsular cataract or any of their combinations. Relative risk ratios and their tolerances were calculated. Risk ratios for some types of cataract were inter-related. Ethnic traits appear to be more important than climatic conditions.