Different eye tonometers are available for the measurement of intraocular pressure. These devices must be checked in Germany by control measurements every 2 years. For this test, special apparatuses were developed by the "Physikalisch-Technische Bundesanstalt" which are checked by comparative measurements during seminars of this institute or during educational events of the "Deutsche Akademie für Metrologie". 50 test apparatuses were compared during a seminar of the "Physikalisch-Technische Bundesanstalt". The measurements of these investigations show the suitability of these devices for the performance of measuring checks of eye tonometers.