An information display device for irradiating a transparent-reflective member with light for forming an image, in order to display a virtual image of the image on the transparent-reflective member, the information display device comprising: a plurality of light sources having different peak emission wavelengths, respectively, which are provided for generating the light for forming the image; a vision-related information input unit configured to receive an input of information relating to vision of a viewer viewing the virtual image; and a luminance adjusting unit configured to adjust luminance of each of the plurality of light sources, independently, based on the information input into the vision-related information input unit; characterized by further comprising an image data generating unit configured to generate data representing a plurality of images for a testing purpose (I1, I2, I3) on a simulated background forming a surrounding image (S), the plurality of images for a testing purpose (I1, I2, I3) having different luminances, respectively, wherein the simulated background and the plurality of images for a testing purpose (I1, I2, I3) are in the same color but the simulated background is of lower luminance, and the images for a testing purpose are located in the center of the simulated background; and an image rendering unit configured to display a virtual image of the plurality of images for a testing purpose, and wherein said information relating to vision of a viewer is an indication of one of the plurality of images for a testing purpose, the one image of the plurality of images for a testing purpose being selected by a viewer viewing the virtual image of the plurality of images for a testing purpose. a plurality of light sources having different peak emission wavelengths, respectively, which are provided for generating the light for forming the image; a vision-related information input unit configured to receive an input of information relating to vision of a viewer viewing the virtual image; and a luminance adjusting unit configured to adjust luminance of each of the plurality of light sources, independently, based on the information input into the vision-related information input unit; characterized by further comprising an image data generating unit configured to generate data representing a plurality of images for a testing purpose (I1, I2, I3) on a simulated background forming a surrounding image (S), the plurality of images for a testing purpose (I1, I2, I3) having different luminances, respectively, wherein the simulated background and the plurality of images for a testing purpose (I1, I2, I3) are in the same color but the simulated background is of lower luminance, and the images for a testing purpose are located in the center of the simulated background; and an image rendering unit configured to display a virtual image of the plurality of images for a testing purpose, and wherein said information relating to vision of a viewer is an indication of one of the plurality of images for a testing purpose, the one image of the plurality of images for a testing purpose being selected by a viewer viewing the virtual image of the plurality of images for a testing purpose. <EOS>