Wide-Angle Observation at a Surgical Microscope

aaaaA microscope for performing an opthalmo-surgical intervention, in particular for a contactless wide-angle observation of an eye during an intervention, is provided. The microscope has a tube having an objective and an ocular, a holding arm, at which the tube is attached such that a movement of the objective with respect to the holding arm along the optical axis of the objective is possible, an optical accessory part between the objective and the eye and a holding device for the optical accessory part. The holding device for the optical accessory part is attached at the holding arm by means of an attachment device in such a way that the holding device does not take part in movements of the objective along the optical axis of the objective. Thereby, when changing the picture angle, a re-adjustment is highly simplified.