Investigated was the significance of semiquantitative tests of the peripheral visual field in glaucoma. For that purpose 793 visual fields of 793 glaucoma patients or glaucoma suspects and 338 visual fields of 338 normal controls (normal central 26 degrees--area) were analysed. Perimetry was performed with an Octopus 201 with the help of program G1, which tests 14 peripheral test locations. In the majority of the 455 glaucoma patients (pathological findings in the central visual field) the periphery was also disturbed. Much to our surprise however, the 338 glaucoma suspects (having normal central visual fields) showed the same frequency of peripheral visual field disturbance as the normals. This holds true for the total peripheral visual field, as well as for the individual test locations. Therefore it makes sense to limit perimetry in glaucoma patients to the central area, provided that the central area is quantitatively measured with an adequate testgrid.