An ophthalmologic apparatus comprising: an examination part including an optical system for optically examining an eye by optical coherence tomography; a moving mechanism configured to move the optical system; an information obtaining part configured to obtain information for carrying out position matching of the optical system to the eye; a controller configured to carry out first control for the moving mechanism based on the information obtained by the information obtaining part to move the optical system, determine whether information optically obtained by the optical system after the first control is appropriate to the examination or not, and when it is determined that this information is not appropriate, carry out second control for the moving mechanism in response to a prescribed trigger to move the optical system, wherein the optical system is configured to split light from the light source into signal light and reference light, scan the eye fundus with the signal light, and detect interference light obtained by composing returned light of the signal light from the eye fundus and the reference light, the examination part is configured to include a cross sectional image forming part configured to form a cross sectional image of the eye fundus based on the detection result of the interference light by the optical system, and the controller is configured to carry out the determination based on the detection result of the interference light or the cross sectional image, the optical system is configured to include an optical-path-length changing part configured for relatively changing optical path length of the signal light and optical path length of the reference light, the controller is configured to, in the determination, while controlling the optical system in such a way as to repeatedly scan the same portion of the eye fundus, control the optical-path-length changing part such that the eye fundus is depicted in a prescribed area in a frame based on the interference light or cross sectional images repeatedly obtained by this control, determine that the information optically obtained by the optical system is not appropriate when the eye fundus is not depicted in the prescribed area, and wherein the controller is configured to control the moving mechanism to move the optical system in a direction perpendicular to a scanning direction when it is determined that the information is not appropriate, before carrying out the second control. an examination part including an optical system for optically examining an eye by optical coherence tomography; a moving mechanism configured to move the optical system; an information obtaining part configured to obtain information for carrying out position matching of the optical system to the eye; a controller configured to carry out first control for the moving mechanism based on the information obtained by the information obtaining part to move the optical system, determine whether information optically obtained by the optical system after the first control is appropriate to the examination or not, and when it is determined that this information is not appropriate, carry out second control for the moving mechanism in response to a prescribed trigger to move the optical system, wherein the optical system is configured to split light from the light source into signal light and reference light, scan the eye fundus with the signal light, and detect interference light obtained by composing returned light of the signal light from the eye fundus and the reference light, the examination part is configured to include a cross sectional image forming part configured to form a cross sectional image of the eye fundus based on the detection result of the interference light by the optical system, and the controller is configured to carry out the determination based on the detection result of the interference light or the cross sectional image, the optical system is configured to include an optical-path-length changing part configured for relatively changing optical path length of the signal light and optical path length of the reference light, the controller is configured to, in the determination, while controlling the optical system in such a way as to repeatedly scan the same portion of the eye fundus, control the optical-path-length changing part such that the eye fundus is depicted in a prescribed area in a frame based on the interference light or cross sectional images repeatedly obtained by this control, determine that the information optically obtained by the optical system is not appropriate when the eye fundus is not depicted in the prescribed area, and