An object of the present invention is to provide an I/O device, an I/O program, and an I/O method which enable easy manipulation. Another object of the present invention is to provide an I/O device, an I/O program, and an I/O method which enable easy manipulation on the basis of ergonomics. The I/O device includes a display device that can generate a stereoscopic image, a depth level sensor that measures a distance to an object, and a control unit that performs display on the display device in accordance with the depth level sensor. A detection region of the depth level sensor has a width in the depth level direction of the depth level sensor, and is composed of a curved measurement region, such that the radius of curvature on the far side in the depth level direction of the depth level sensor is different from the radius of curvature on the near side in the depth level direction of the depth level sensor.