An ophthalmologic apparatus comprising: a wavelength sweep type light source that is configured to emit light having a wavelength that changes with a predetermined period; an optical measurement system configured to radiate first light from the light source to inside an eye to be examined and to guide first reflected light from the eye; an optical reference system (22, 24) configured to radiate second light from the light source to a reference surface and to guide second reflected light from the reference surface; a photo detector configured to detect interfering light between the first reflected light from the optical measurement system and the second reflected light from the optical reference system (22, 24); and a processor configured to determine a first position of a first measuring portion inside the eye based on the detected interfering light, and a second position of a second measuring portion inside the eye based on the detected interfering light, and to determine an axial length from the first position to the second position, characterised in that the optical measurement system comprises a focal point adjustment mechanism that is configured to change a focal point of the first light in its focal aim direction, and a 0 point adjustment mechanism configured to change a 0 point, in which an optical path length between the light source and the eye matches an optical path length between the light source and the reference surface, the processor is further configured to determine the first position of the first measuring portion based on the first detected interfering light obtained when a wavelength of the emitted light from the light source changes with the predetermined period in a state where the focal point and the 0 point are matched with the first position, the processor is further configured to determine the second position of the second measuring portion based on the second detected interfering light obtained when a wavelength of the emitted light from the light source changes with the predetermined period in another state where the focal point and the 0 point are matched with the second position, the first position of the first measuring portion is one of a front or rear surface of a cornea of the eye, a front or rear surface of a crystalline lens of the eye, and a surface of a retina of the eye, the second position of the second measuring portion is one of the front or rear surface of the cornea of the eye, the front or rear surface of the crystalline lens of the eye, and a surface of the retina of the eye, and the second position is different from the first position. a wavelength sweep type light source that is configured to emit light having a wavelength that changes with a predetermined period; an optical measurement system configured to radiate first light from the light source to inside an eye to be examined and to guide first reflected light from the eye; an optical reference system (22, 24) configured to radiate second light from the light source to a reference surface and to guide second reflected light from the reference surface; a photo detector configured to detect interfering light between the first reflected light from the optical measurement system and the second reflected light from the optical reference system (22, 24); and a processor configured to determine a first position of a first measuring portion inside the eye based on the detected interfering light, and a second position of a second measuring portion inside the eye based on the detected interfering light, and to determine an axial length from the first position to the second position, characterised in that the optical measurement system comprises a focal point adjustment mechanism that is configured to change a focal point of the first light in its focal aim direction, and a 0 point adjustment mechanism configured to change a 0 point, in which an optical path length between the light source and the eye matches an optical path length between the light source and the reference surface, the processor is further configured to determine the first position of the first measuring portion based on the first detected interfering light obtained when a wavelength of the emitted light from the light source changes with the predetermined period in a state where the focal point and the 0 point are matched with the first position, the processor is further configured to determine the second position of the second measuring portion based on the second detected interfering light obtained when a wavelength of the emitted light from the light source changes with the predetermined period in another state where the focal point and the 0 point are matched with the second position, the first position of the first measuring portion is one of a front or rear surface of a cornea of the eye, a front or rear surface of a crystalline lens of the eye, and a surface of a retina of the eye, the second position of the second measuring portion is one of the front or rear surface of the cornea of the eye, the front or rear surface of the crystalline lens of the eye, and a surface of the retina of the eye, and the second position is different from the first position.