Patients at the Department of Ophthalmology, University of Bern, will be included after informed consent. The study has been approved by the local ethical committee. Routine ophthalmologic examination will be performed and inclusion criteria evaluated. Measurements will be taken with the two tonometers in random order. Prior to pressure measurement, central corneal thickness will be measured with a non-contact method (Optical Low Coherence Reflectometry, OLCR pachymeter, Haag-Streit, Koeniz, Switzerland).