1. A diagnosis supporting device comprising: a display; an imaging unit configured to capture a subject; an eye gaze detector configured to detect an eye gaze direction of the subject from a captured image captured by the imaging unit; a gaze point detector configured to detect a gaze point of the subject in a display region of the display, based on the eye gaze direction; an output controller configured to display, on the display, a diagnosis image that includes a person image and a geometric pattern image, and in which at least one of contrast, color density, and a degree of transmittance of the person image or the geometric pattern image is changed over time; and an evaluator configured to calculate an evaluation value of the subject, based on the gaze point detected by the gaze point detector when the diagnosis image is displayed.