DURING 1948 and 1949, 387 cases of detachment were referred to the Retina Service of the Massachusetts Eye and Ear Infirmary for treatment. Cases of aphakia numbered 88, or 23 per cent. In eight cases there were bilateral aphakia and detachment. The purpose of this paper is to analyze our findings and discuss our results in cases of detachment and aphakia. I shall attempt to determine some of the important factors in the causation of the disease. Practical points which will be discussed may help in making an early diagnosis and in facilitating examination of the fundus. Surgical technic will not be discussed. In eyes with detachment and aphakia, what is the relation between the aphakia and the detachment? Is the second a complication of the first; are they two independent conditions which happen to coexist in a certain number of patients, or are detachment and cataract closely related because