The changes of retinal illuminace, circadian rhythm and blue light hazard with age were studied. The normalized spectral distributions of four common displays with white and blue background were measured with the spectrometer. The retinal illuminance factor, blue light hazard factor and circadian factor were calculated based on the lens spectral transmission of different ages. The relationships between these three factors and age were obtained. It is shown that the above three factors decrease rapidly as the age increases for the same light emitting diode backlight display. The retinal illuminance factor changes little with the type of display for human of the same age. For the younger, The blue light hazard factor and the circadian factor vary greatly with the displays, especially for the blue background. However, for the older, the variations of blue light hazard factor and the circadian factor are small for different displays.