An image projection device includes: a light source emitting a light beam; an image input unit inputting image data; a control unit generating an image light beam based on the input image data, and controlling emission of the image light beam from the light source; a scan unit scanning the image light beam emitted from the light source; and a projection optical member illuminating a retina of an eyeball of a user with the image light beam scanned by the scan unit, and projecting an image onto the retina, wherein a diameter of the image light beam at a time when the image light beam enters a cornea of the eyeball is not smaller than 310 μm and not larger than 800 μm, and a user having an original visual acuity in a range of 0.04 to 1.2 has an acquired visual acuity of 0.4 or higher.