Ophthalmologic apparatus

Abstract

An ophthalmologic apparatus comprises a light source 12, an optical measurement system 13 that radiates first light from the light source to inside an eye to be examined and guides first reflected light from the eye, an optical reference system (24, 22) that radiates second light from the light source to a reference surface and guides second reflected light from the reference surface, a photo detector 26 that detects interfering light between the first reflected light from the optical measurement system and the second reflected light from the optical reference system, and a processor that determines a position of a measuring portion of the inside of the eye based on the detected interfering light. The optical measurement system comprises an incident angle changing member 46 that changes an incident angle of the first light radiated to the eye within a predetermined angular range relative to an axis of vision of the eye.

What is claimed is: 
     
         1 . An ophthalmologic apparatus comprising:
 a light source;   an optical measurement system configured to radiate first light from the light source to inside an eye to be examined and guides first reflected light from the eye;   an optical reference system configured to radiate second light from the light source to a reference surface and guides 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; and   a processor configured to determine a first position of a first measuring portion inside the eye based on the detected interfering light,   wherein the optical measurement system comprises an incident angle changing member configured to change an incident angle of the first light radiated to the eye within a predetermined angular range relative to an axis of vision of the eye,   the incident angle changing member is configured to scan the incident angle within the predetermined angular range during a measurement,   the photo detector is configured to detect interfering light of each scan angle and output an interference signal of each scan angle to the processor,   the interference signal of each scan angle includes a first signal component, the first signal component being created by the second reflected light and reflected light from the first position of the first measuring portion, and   the processor is configured to determine the first position of the first measuring portion based on only the first signal component of the interference signal with respect to a first angular range with increased intensity of the interference signal which is higher than a first predetermined intensity.   
     
     
         2 . The ophthalmologic apparatus as in  claim 1 , wherein
 the processor is configured to determine a second position of a second measuring portion inside the eye based on the detected interfering light,   the interference signal of each scan angle includes a second signal component, the second signal component being created by the second reflected light and reflected light from the second position of the second measuring portion, and   the processor is configured to determine the second position of the second measuring portion based on the second signal component of the interference signal of each scan angle.   
     
     
         3 . The ophthalmologic apparatus as in  claim 2 , wherein
 the first position of the first measuring portion is one of; a front or rear surface of a cornea of the eye, and a front or rear surface of a crystalline lens,   the second position of the second measuring portion is a surface of a retina of the eye, and   the processor is configured to determine an axial length from the first position to the second position.   
     
     
         4 . The ophthalmologic apparatus as in  claim 1 , wherein
 the processor is configured to determine a third position of a third measuring portion inside the eye based on the detected interfering light,   the interference signal of each scan angle includes a third signal component, the third signal component being created by the second reflected light and reflected light from the third position of the third measuring portion, and   the processor is configured to determine the third position of the third measuring portion based on only the third signal component of the interference signal with respect to a third angular range with increased intensity of the interference signal which is higher than a third predetermined intensity.   
     
     
         5 . The ophthalmologic apparatus as in  claim 4 , wherein
 the first position of the first measuring portion is one of; a front or rear surface of a cornea of the eye, and a front or rear surface of a crystalline lens,   the third position of the third measuring portion is different from the first position of the first measuring portion and one of; a front or rear surface of a cornea of the eye, and a front or rear surface of a crystalline lens, and   the processor is configured to determine an axial length from the first position to the third position.