Programs for the early detection of glaucoma are becoming widely practiced in an effort to reduce the heavy toll of blindness from this cause. Information relating to the efficiency of various screening levels of intraocular pressure is important to such programs. Such information was obtained by giving complete ophthalmologic examinations to 1,062 persons randomly selected from 9,461 persons who had been screened for glaucoma in the City of Memphis Hospitals. Sensitivity and specificity percentages for various levels of intraocular pressure were calculated for the group as a whole and also for component groups below and above 55 years of age. Differences of practical importance were observed between the latter groups.