The detection and grading of cataract: an epidemiologic perspective.

A major limitation in epidemiologic research on the etiology of cataracts is the lack of a standardized method for detecting and grading in vivo cataracts. This article reviews both clinical and photographic methods for determining the presence and severity of cataracts. Clinical methods, involving uniform training of examining ophthalmologists and standard protocols, do not insure reproducibility in detecting or grading cataracts. Photographic methods appear to be more reliable, but more research is needed to develop methods for accurate interpretation.