1. A detection apparatus comprising: a display; an imaging unit configured to image a subject; an eye gaze detector configured to detect an eye gaze direction of the subject based on a captured image captured by the imaging unit; an output controller configured to display a diagnostic image that includes a person image and a geometric pattern image, onto the display; and a gaze point detector configured to: set a first determination area at a region including a face portion in the person image, detect a first gaze point as a gaze point of the subject in the first determination area based on the eye gaze direction, set a second determination area at a region in the geometric pattern image, and detect a second gaze point as a gaze point of the subject in the second determination area, wherein the first determination area and the second determination area are configured to be set in such a manner that a gazing time difference between a neurotypical subject and a subject with developmental disorder becomes significant.