PROBLEM TO BE SOLVED: To quickly and highly-precisely detect alignment by an inexpensive constitution. SOLUTION: This ophthalmologic instrument is provided with a CCD camera 46 photographing an anterior ocular segment image of a subject eye E of the optometry, and a CPU detecting a positional deviation of a measurement part relative to the subject eye E of the optometry using image signals of the image of the anterior ocular segment of the subject eye E from the CCD camera 46. The CCD camera 46 outputs the image signals to an image memory 69 for every odd number field and even number field by interlace signals. The CPU detects the positional information using the image signals of either one of the odd number field or the even number field and corrects the position information according to the field used for the detection.
