Biele LED diódy môžu poškodiť sietnicu, zmeniť biologické hodiny?
LED is a very good light source, but some people will misunderstand and think that LED is harmful to human eyes. There are some LED ceiling downlights and LED ceiling spotlights used in households, but some "experts" dare not use them. A professor who is engaged in LED research said to me: "We don't use LED light sources in our house. It's not that I don't want to use it, but my wife doesn't want to use it. She thinks that LEDs may be harmful to human eyes, so she is very opposed to using LEDs." This has caused many LED ceiling downlight manufacturers and LED ceiling spotlight manufacturers to be injured!
In addition to visual effects, lighting also produces biological effects. Why do we get up late in winter and early in summer? This is actually because light controls our biological clock. When the blue light is strong, people have no desire to sleep; on the contrary, when the blue light is weak, it is conducive to people's sleep. Therefore, blue light will have an impact on human biological rhythms. At present, most white LEDs use blue LEDs to excite YAG phosphors. The peak wavelength of blue light radiation has a relatively large overlap with the retinal blue light damage characteristic curve and the human body's non-visual sensitivity curve. In this way, when white LEDs are used indoors, some people worry that they will damage the retina and disturb the biological clock.
It is reported that Professor Van Bommel, former chairman of the International Commission on Illumination (CIE), has a very positive attitude towards the use of LEDs and has done a lot of research work. In an article titled "Lighting Quality and Energy Efficiency", he focused on the impact of LED's blue light on people. After careful calculation, the result is that a white LED with a color temperature of 2700K and a color rendering index above 80 emits less blue light than an incandescent lamp that produces the same luminous flux. He believes that white LEDs with a color temperature of 2700K3000K and a color rendering index above 80 can be used indoors with confidence.
Dr. Tian Yan from the Department of Dermatology of the Air Force General Hospital of the Chinese People's Liberation Army said that now, the CCTV news studio has used LED lights for lighting. In the LED lighting research project of the CCTV studio, Dr. Tian Yan invited more than 30 volunteers to undergo 30-day irradiation experiments. Irradiated once for 30 consecutive days. The results showed that there was no statistical difference in the changes of the volunteers' skin color, that is, the skin color of the human body did not change under the LED light; in addition, the LED light source had no significant effect on the water content of the stratum corneum and TEWL. The experimental results prove that LED lighting is safe for the skin.
At the same time, she also conducted a comparative experiment, namely "the effect of fluorescent lamps on human skin". The results show that long-term illumination of fluorescent lamps may cause damage to the skin. The first is that the indicators of skin color have changed, the L value has decreased, the a value has increased, the M value has increased, and the E value has increased; the skin color has become black and red; at the same time, the water content of the stratum corneum has a downward trend; There were also some changes in the tissue structure of the skin when the dose was increased.
