A diagnosis supporting device comprising: an imaging unit (202,204) that images a subject; an eye gaze detector that detects an eye gaze direction of the subject from an image imaged by the imaging unit (202,204); and a gaze point detector that detects a gaze point of the subject in a display area of a display based on the eye gaze direction, characterized in that the diagnosis supporting device further comprises: an output controller configured to cause the display area to display an image composed by superposing a pattern image that is an image including a geometric pattern onto a partial area of a natural image that is an image of a natural object or something associated with a natural object, as a diagnostic image, and perform control such that a partial image displayed in an area adjacent to the partial area within the partial image included in the natural image is displayed in a display mode similar to or matching a display mode of the pattern image, wherein the pattern image includes a shape that is close to continuous with an outline of a part of an object included in the natural image. an imaging unit (202,204) that images a subject; an eye gaze detector that detects an eye gaze direction of the subject from an image imaged by the imaging unit (202,204); and a gaze point detector that detects a gaze point of the subject in a display area of a display based on the eye gaze direction, characterized in that the diagnosis supporting device further comprises: an output controller configured to cause the display area to display an image composed by superposing a pattern image that is an image including a geometric pattern onto a partial area of a natural image that is an image of a natural object or something associated with a natural object, as a diagnostic image, and perform control such that a partial image displayed in an area adjacent to the partial area within the partial image included in the natural image is displayed in a display mode similar to or matching a display mode of the pattern image, wherein the pattern image includes a shape that is close to continuous with an outline of a part of an object included in the natural image. an output controller configured to cause the display area to display an image composed by superposing a pattern image that is an image including a geometric pattern onto a partial area of a natural image that is an image of a natural object or something associated with a natural object, as a diagnostic image, and perform control such that a partial image displayed in an area adjacent to the partial area within the partial image included in the natural image is displayed in a display mode similar to or matching a display mode of the pattern image, wherein the pattern image includes a shape that is close to continuous with an outline of a part of an object included in the natural image. cause the display area to display an image composed by superposing a pattern image that is an image including a geometric pattern onto a partial area of a natural image that is an image of a natural object or something associated with a natural object, as a diagnostic image, and perform control such that a partial image displayed in an area adjacent to the partial area within the partial image included in the natural image is displayed in a display mode similar to or matching a display mode of the pattern image, wherein the pattern image includes a shape that is close to continuous with an outline of a part of an object included in the natural image.