Fig. 6. A most reliable sign in angle-closure glaucoma is the unreactive pupil in the mid-dilation. Conjunctival and ciliary vascular engorgement, as well as epithelial corneal edema, is present. In this eye, no atrophy of the iris is visible, but the iris sphincter is unreactive, presumably as a result of ischemia caused by the elevated intraocular pressure. If high pressure is relieved before permanent atrophy of the iris occurs, the pupil will again become reactive. (Courtesy of Ayerst Laboratories and Dr. H. Saul Sugar)