It is reported that white cold led and blue LED are harmful to eyes and should be banned. These LEDs are mainly used for decoration, and their blue light intensity is far beyond the natural lighting and traditional lighting. These high-intensity blue light can cause damage to both the pigment epithelium and the sensory layer of the retina, thus accelerating the aging of the retina and increasing the risk of macular degeneration. The most vulnerable group of LED is children under 10 years old. Children of this age group have neither turbid lenses nor macular pigment, so they lack resistance to blue light.
LED light is produced by mixing blue chip with external yellow fluorescent powder, which makes the content of blue light in LED light relatively high. Blue light refers to the blue light band of 400-500 nm. If the brightness is too high, the eye may cause photochemical damage to the retina after looking directly at the light source for a long time. The harm degree of blue light depends on the amount of blue light accumulated and received by the human eye under the light. According to the national regulations, the color temperature of LED lighting shall not be greater than 4000K. However, due to the high light efficiency and low cost of high color temperature led light source, there are many high color temperature products in the market.
Color temperature is the most general index of spectral quality of light source. The color temperature of “warm light” is lower than that of “cold light”. When the color temperature increases, the proportion of blue radiation increases, and the blue light increases. At the same time, brightness also affects the proportion of blue light. Generally speaking, fluorescent lamps and LED lamps with the same color temperature, as long as the brightness of the latter is not more than three times that of the former, are basically harmless. However, for some LED lamps that are too bright, the blue light ratio may exceed the safety value. With the growing maturity of LED technology, manufacturers no longer need to improve the color temperature and power of lamps to achieve high brightness, and objectively reduce the possibility of excessive blue light.