A wide range within a subject eye is observed while a burden on a subject of whom the subject eye is part is moderated. In an optical system that deals with light reflected from the fundus of the subject eye, a first optical system that pertains to a field of view of a fundus central portion centered on an optical axis is used as a standard optical system. The optical system can be switched by a replacement mechanism from the first optical system to a second optical system that pertains to a field of view of a fundus surroundings portion surrounding the fundus central portion.