ABSTRACT
The human eye observes light images on phosphor screens. The human eye has adjusted daytime scenes for 7 million years. These scenes are made by sunlight reflected onto various materials. The light consists of photons that have energy; and the number of photons in daytime scenes can be determined from the measurement of that energy. The photon number is 10
·s
cm
[4]. If the images projected onto the screen in display devices are made by the photon density of 10
·s
cm
, one can comfortably watch the images on the phosphor screen in illuminated rooms.
