The present invention relates to an ophthalmologic apparatus for acquiring depth information of an eye including a light source； a measurement optical path guiding measurement light； a reference optical path generating reference light； and a detector generating a detection signal containing an interference signal of the measurement light via the measurement optical path and the reference light coming from the reference optical path； an actuator driving at least part of the interference optical system to vary an optical path length difference between the measurement optical path and the reference optical path； a standard optical system including optical members disposed corresponding to the optical path length differences in one of the measurement optical path and the reference optical path. Optical members guide part of the measurement light or the reference light to the detector.
