During screening procedures in Nordrhein-Westfalen in 1976 more than 100,000 persons had their, i.o. pressure measured for the first time. The results are now available from 66,957 subjects. From these 59,037 had a normal i.o. pressure, 6.941 had raised i.o. pressure, and in 979 subjects the i.o. pressure was very high. This was the first time that screening procedures on a large scale were carried out exclusively with the applanation tonometer. This procedure was carried out as part of a campaign to make the illness of glaucoma better known to the public.