The optic disc of nine patients with typical glaucomatous disc damage and ten normal controls has been studied by means of the Optic Disc Analysis program of the Topcon Image-net System. Vertical, horizontal and average cup/disc ratio (VC/D, HC/D, AC/D), disc, cup, rim area (DA, CA, RA), cup volume (CV) have been evaluated and the coefficient of variation (COV) of multiple measurements was calculated. For intra-observer intra-image variability assessment, sterovideographs of each disc were taken once and analyzed 10 times (COV range: 1.39-12.08%). Intra-observer interimage variability was evaluated on eight stereovideographs of each disc taken at one minute intervals (COV range: 1.63-96%). Inter-observer intra-image measurements were taken on each disc by 5 different observer (COV range: 1.28-27.08%).