An object is to provide an image display device which exercises a function of adjusting a biological clock without changing a visibility of an image. An image display device (A) for displaying an image by radiating a light from a light source (1) to a display portion (2) includes: the light source (1) having a radiation emitter for emitting a light having a wavelength band of 445 to 480 nm; and control means (3) for controlling an intensity of the light having the wavelength band; in which a display portion includes an area (21) on which a predetermined image is displayed; and an area (22) on which an image for which the intensity of the light having the wavelength band is controlled by the control means (3) separately, independently of each other.
