During normal indoor activities, people not only need their visual function to be satisfied, but also need to feel comfortable visually, which is defined as a psychological needs for the lighting environment. Normally these good-quality lighting environments should not be bothered with direct glares and indirect glares, with right color temperatures, with comfortable arrangement of lamps. In the aspect of glare control, white-ray LED lamps have both advantages and challenges. Since LEDs have smaller emitting points and beam angles, it is relatively easy to control the direction of the beam. But on the other hand, as a kind of highly concentrated lighting sources, if the maximum light distribution of LED lamps cannot be disposed properly, the entire lamps will send out some glares which exert bad influence on human eyes. It is showed that the discomfort glare will not only case a decline in the efficiency of your works, but can also cause visual fatigue, headaches and other adverse reactions. If choosing RGB LED chips as lighting sources, manufacturers can produce white-ray LED lamps with arbitrary color temperatures. But this will affect the comfort and aesthetics of the whole field of view. Blue-ray LEDs with YAG powder will generate high color temperature rays. In order to maintain good illumination effects, the color temperature of lighting sources must be adapted to the illumination requirements. Higher color temperatures will definitely impact the indoor white-ray LED lighting applications. Because it requires a correspondingly higher illuminance to make people feel comfortable. Besides,
People’s physiological needs for indoor lighting are mainly in the health part. It is cleared that a long-term UV radiation can have skin adverse effects on human bodies. Besides, there are two other health-hazard optical influences that can be easily ignored: visual effects and effects on the circadian rhythm system. There are two effects that closely associated with white-ray LED lights for indoor lighting: the blue-ray hazardous effect on retina and the light affect the circadian rhythm system by suppressing the secretion of melatonin. Usually, UV caused damages on the front of our eyes (cornea). The wavelength of blue rays is longer than that of UV rays. Thus they can easily get through the eye ball and reach end to the retina. Furthermore, blue-rays have the highest unit energy among visible ranges, can easily burn the retina and lead to cataracts. On the other hand, the melatonin secretion is affected by light. The disorder of melatonin secretion will cause physiological imbalance, even cancers or other diseases in some serious conditions.