an apparatus for observing an eye of an examinee by imaging the eye , includes an irradiation optical system ; an imaging optical system ; a monitor ; and a display control part , wherein the imaging optical system includes a wavefront detector which receives the beam reflected by the objective part to detect wavefront aberration thereof and a wavefront compensator adapted to compensate the wavefront aberration based on a detection result of the wavefront detector , the wavefront compensator being placed within an optical path of the imaging optical system excepting a common optical path with the irradiation optical system .