Optical viewing device for inwardly or outwardly reflecting image data provided with additional diaphragms

The invention relates to an optical observation instrument, for example a (stereo) operation microscope, having an additional shutter (4) in a main beam path (2b), arranged between an output-reflection beam splitter (3) and an observer eyepiece (5), for respectively connecting and disconnecting the observer (8a), without affecting the output-reflected signal. As a special refinement, a special shutter design is described, which makes it possible to respectively connect and disconnect the two main beam paths (2a, 2b) and involves an override function (quick reset) for opening both beam paths.