Simultaneously performed ophthalmoscopy and perimetry by microperimetry using the Scanning Laser Ophthalmoscope eliminates some of the classical problems involved in transformation techniques in perimetry such as: optical distortions, unsteady fixation and alignment. Almost all reports published on microperimetry have addressed chorioretinal diseases, with only a few patients in each study. No reports have studied the normal values of this method. To evaluate the reliability of microperimetry, 30 healthy subjects-10 subjects from each of the age group: 40-49 years (male/female ratio: 4/6), 50-59 years (m/f ratio: 5/5) and 60-69 years (m/f ratio: 5/5)-were repeatedly examined with microperimetry and automatic perimetry performed by the Octopus macular program M1. The results of the present study of microperimetry show that the standard deviation of the interindividual variance component was 1.36, that the standard deviation of the intraindividual variance component was 0.94 and that a test result obtained by microperimetry in any of the two locations studied can be related to a test result obtained by Octopus M1 in the same location.