Eye Refractive Power Measuring Apparatus and Calibration Method of Eye Refractive Power Measuring Apparatus

An eye refractive power measuring apparatus comprising:

• a light projecting optical system that projects a measuring beam for use in measurement of eye refractive power on a fundus of a subject's eye;
• a light receiving optical system that causes a light receiving unit to receive reflected light from the fundus;
• a focusing unit that forms an image of the reflected light on the light receiving unit by moving a focal position;
• a calibration optical system that projects a calibration beam for use in calibration of the focusing unit;
• a focus control unit that outputs to the focusing unit a control signal for controlling movement of the focal position;
• and
• an arithmetic unit that,
• based on a relation of the control signal obtained when the calibration beam is projected and a calibration value that is an output of the light receiving unit, and a correspondence relation of the calibration value and the eye refractive power obtained in advance, calculates a correlation of the control signal and the eye refractive power, and,
• based on the control signal obtained when the measuring beam is projected, a measured value that is an output of the light receiving unit, and the correlation, calculates the eye refractive power.