Clinical Significance of Some ome Entoptic Ph enomena

Abstract
Entoptic phenomena are, to the average ophthalmologist, items of physiologic curiosity rather than useful clinical tools. Scheerer's phenomenon, which renders red blood cells circulating in the paramacular region visible, and Haidinger's brushes, which test the integrity of the nerve fibers of Henle's layer, are two of the entoptic phenomena which have advanced from experimental investigation to clinical application. They have proved to be of considerable practical importance, and it is unfortunate that they have not gained the popularity they deserve. We have applied these phenomena to to the study of several patients at the New York Eye and Ear Infirmary and have endeavored to analyze and interpret the results. SCHEERER'S PHENOMENON In one of his fundamental articles, Scheerer states that more than a dozen authors, among whom are Helmholtz and Purkinje, have described the phenomenon now known as Scheerer's phenomenon. Nearly all of them made their observation by just looking