An apparatus for retaining an optical viewing device, for example a microscope (8), on a stand having a parallelogram carrier arm (5a, 5b, 5c, 5d), comprises an adjustable-length strut (6) acting through a pivot point of the carrier arm and an opposite link of the carrier arm. The strut (6) provides, in different variants, inclination adjustment, and/or vibration damping of the carriers arm.