small temporal coherence here the first light source part 11 is for example a super luminescence diode sld and a point light source having high luminescence can be obtained incidentally the first light source part 11 is not limited to the sld and for example a laser having a large spatial coherence and a large temporal coherence can also be used by combining a rotary prism described later further an led having a small spatial coherence and a small temporal coherence can also be used if light quantity is sufficient by inserting for example a pinhole or the like at a position of a light source in an optical path besides in order to uniform the irregular characteristics of reflected light from the retina a wedge shaped rotary prism d prism 16 is inserted in the illumination optical system since an illuminated portion on the retina is operated by the rotation of the rotary prism the reflected light from the retina becomes uniform and it is possible to uniform the received light flux point image of the light receiving part the first light receiving optical system 20 includes for example a collimator lens 21 a hartman plate 22 as a conversion member for converting a part of a light flux first light flux reflected and returned from the retina 61 of the eye 60 to be measured into at least 17 beams and a first light receiving part 23 for receiving the plural beams converted by the hartman plate 22 and is for guiding the first light flux to the first light receiving part 23 besides here a ccd with little readout.