In 1941 it was recognized that a massive growth of embryonic connective tissue occurring in the meshwork of a persistent tunica vasculosa lentis is linked with prematurity.1To my knowledge there are at least 162 cases at the present time. Dr. Stewart Clifford2has found that 12 per cent of the infants weighing 3 pounds (1,360 Gm.) or less at birth develop this disease. This percentage, based on less than 50 cases of prematurity, can be considered only a trend. If the true percentage of infants developing this disease is about 10, approximately 6003cases are to be expected in this country each year, which, if some prophylaxis is not found, will add materially to the 175,000 blind.4 Typical well developed cases show seven characteristic findings: There is opaque vascularized tissue behind the crystalline lens in which the vessels tend to radiate from a central