Abstract: Using the principle of grating spectroscopy, the harmful blue light is separated from the lights of liquid crystal display. By measuring the illumination value representing the damage of blue light, we provide a simplified method of evaluating the blue light hazard from the screen. Through the massive measurement of blue light hazard of liquid crystal on different conditions, some conclusions are drawn about the hazard. And some suggestions are raised that less liquid crystal should be used as well as used properly.

Key words: liquid crystal display, blue light, photochemical damage