We studied 82 cases of essential iris atrophy. The findings support some traditional concepts of this complex spectrum of disorders, but conflict with others. Corneal abnormality appeared early and may be the primary disorder. A corneal endothelial disturbance was present in 55% of cases and corneal edema was present in 50%. Peripheral anterior synechiae occurred in all but one of the cases studied by gonioscopy. The pupil was distorted in 71% of the cases and was usually pulled in the direction of the most prominent synechia. The iris was stretched with stromal atrophy in 71%. Iris holes occurred in 33%. The degree of corneal and iris changes occurred as a spectrum of disorders. The prognosis for most patients with essential iris atrophy is slow progression with eventual involvement of vision because of corneal edema, secondary glaucoma, or both. Treatment of increased IOP was required in 77% of our cases, and 44% required surgical intervention.