The epidemiology of cataract

The epidemiologic study of cataract and lens opacity has made great strides in determining the magnitude of the problem and the burden cataract places on human populations. This article describes the considerable progress made in characterizing different opacity phenotypes, differences between ethnic and racial populations, and identifying risk factors with public health importance. Future research must address the questions of why these population differences exist, using creative collaborations in diverse population laboratories. While the risk of cataract can be reduced, it cannot be prevented. Therefore, continued emphasis on health services research is needed, using effective methodologies to identify disparities and inequities in access to surgical treatment for cataract. Links with systemic models of aging are at the forefront of research and deserve special attention for the broader implications that may be revealed by findings markers for early senescence.