An ophthalmic apparatus includes a control unit configured to control a scanning unit so that scanning lines of a first field and scanning lines of a second field are alternately arranged in a direction crossing the scanning lines, and a detection unit configured to, in a case where one of first front images of the first field is selected as a reference image, detect movement of the subject's eye using information indicating a position gap between the reference image and the first front images, and detect the movement of the subject's eye using information indicating a position gap between the reference image and second front images of the second field and information indicating a difference in position between the first field and the second field.