A detection apparatus includes a display (101), an imaging unit (102) an eye gaze detector (354), an output controller (356), and a gaze point detector (355). The imaging unit (102) images a subject. The eye gaze detector (354) detects an eye gaze direction of the subject based on a captured image captured by the imaging unit (102). The output controller (356) displays a diagnostic image that includes an own person image including a face image and a geometric pattern image, onto the display (101). The gaze point detector (355) detects a first gaze point as a gaze point of the subject in the person image based on the eye gaze direction and detects a second gaze point as a gaze point of the subject in a region that includes at least one of a center of a geometric pattern, a characteristic portion of the geometric pattern, a portion in which density of lines forming the geometric pattern is higher than other portions, and a portion in which the geometric pattern changes, in the geometric pattern image.
