"Blu-ray Harm" Conversation Record

　　On May 28, 2021, the "Blue Light Hazard Conference" was held in the WeChat group of experts from the Guangdong Opelectronic Technology Association. At the conference, experts released insights on the pic of "Blue Light Hazards" and jointly explored light health. The following is the record of the conference:

　　Professor Xiaodong Zheng (Zhejiang University):

　　Professor He, personal opinion is that there are not only "blue light hazards" during the day, but also "ultraviolet hazards (UV-A, UV-B, UV-C)", infrared hazards, and cosmic rays hazards.

　　Professor Wen Shangsheng, Chairman (South China University of Technology, Guangdong Opelectronic Technology Association):

　　Personal understanding is that man is the product of nature's evolution, and light of any wavelength is indispensable  the human body. However, any light intensity should have a "degree". If it is o much, it will not be enough. If it exceeds a certain "threshold", it will definitely have different degrees of influence.

　　Professor Xiaodong Zheng (Zhejiang University):

　　I very much agree with Professor Wen's suggestion of moderation! Different functions of the human body, different parts, and different ages have different needs for light. For example, ultraviolet rays are harmful  the eyes and accelerate cataracts; but without ultraviolet rays, it will cause calcium deficiency, which is equally harmful  health.

　　In most cases, the blue light hazard can be ignored. As for the impact of watching mobile phones at night mentioned by Professor Zhang, it largely depends on whether there are other light sources around. Without other light sources, the pupils of the eyes in a dark environment are opened relatively large, which will have an impact.

　　Academician Jiang Fengyi and Vice President (Nanchang University):

　　Lighting, work and rest should be different.

　　Professor Lin Yandan (Fudan University):

　　The blue light hazard mainly depends on:

　　1. The effective amount of blue radiation entering the human eye (related  the wave spectrum);

　　2. Duration of radiation (related  observation conditions and behavior). Mobile phones or pad screens usually contain a lot of effective blue light. Coupled with long-term observation at close distances, the content will lead  long-term inattention, and the cumulative effect of damage will be more prominent.

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　The blue light harm BLH is expressed according  the mechanism, dose = irradiance * time, which is called AMD in medicine.

　　This formula is a simplified calculation. For light, energy destruction is the basic mechanism, then, dose = phon flux density * time. This is also the mechanism of ultraviolet sterilization, which is the cumulative amount of energy exchanged with the recepr. The greater the phon energy, the shorter the damage time.

　　Human cone cells are limited, so as long as the dose is reached, light damage will destroy the cone cells, and it is irreversible. From this point of view, as long as the green light reaches the dose, it also destroys the cone cells.

　　Professor Kaijun He (Xiamen LED Promotion Center):

　　Now the "blue light hazard" has been expanded  prevent blue light everywhere, and the blue light in the daytime white light is beneficial.

　　Please refer  the hisrical data. The term "blue light hazard" comes from the laser field. It specifically refers  the phochemical damage  the eyes caused by the peak of blue light in the 435-440nm band. It is a proper term. In 2017, CIE has a position statement on "blue light hazard" , You can find it.

　　I think that the health benefits of blue light in white light cannot be ignored. Blue light is necessary for imaging. According  Hering's four-color theory, blue-yellow is the antagonistic color. If the blue light is filtered, it will destroy the antagonistic balance of nerves. In addition, Australian scientists have studied that blue light can activate the production of seronin, which is the raw material for the synthesis of melanin at night. Seronin and melanin are the most important neurotransmitters for regulating "sleep". My goal is  require RG0 or RG1 for classroom lighting during the day!

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　The current biosafety standards recommended by the state are not scientific, and domestic scholars oppose it. Phometry and colorimetry cannot explain the health problems of light sources.

　　Professor Wu Xinmin (Anhui Hanshi Laser Technology Co., Ltd.):

　　The damage  human eyes is mainly blue light, so reducing the blue light of the screen from entering human eyes is a basic measure  reduce the damage  human eyes. It is medically proven that the damage  human eyes is caused by blue light.

　　Professor Kaijun He (Xiamen LED Promotion Center):

　　Let's focus on it now, let's talk about daytime, should natural light filter blue light? Should the classroom lighting during the day reduce the blue light or use a black body  radiate the light curve?

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　Depends on the content of blue light energy, blue light damage must be serious in plateau areas.

　　Professor Kaijun He (Xiamen LED Promotion Center):

　　You can also check the test report of Teacher Yu Anqi.

　　Professor Junping Zhang (Fudan School of Computer Science):

　　I guess the emphasis on blue light is related  the relatively small number of blue light-sensitive cells in the retina?

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　For the impact of light on health, it is still necessary  refer  medical data and use statistics  analyze it more objectively.

　　Professor Xiaodong Zheng (Zhejiang University):

　　CIE’s official position is: “There is literature that blue light exposure may be related  the risk of age-related macular degeneration.” This statement is currently speculative and has not been supported by peer review.

　　Professor Kaijun He (Xiamen LED Promotion Center):

　　Therefore, I used  say that sunlight is the best light and natural light is the best light. It is wrong. It should be reviewed. CIE has stipulated standards for natural light. I think the plains at 30 degrees north latitude are the most suitable for life, and the natural light in these places is the best. President Xu Dong's Guangzhou is o hot, not suitable for the natural light of your life!

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　BLH cannot provide experimental data, which is ethical and legal constraints, but there is a statistical probability.

　　Professor Qian Weiguo (Shanghai Ocean University):

　　What exactly is the hazard here?

　　Chairman Xu Dong (Shenzhen Facility Agriculture Industry Association):

　　Mild color blindness and severe macular degeneration.

　　Professor Wu Ligang (Abeni):

　　I have been thinking about a question. The LED light in the living room is turned on, and it is no problem  look at the mobile phone. Turn off the lights in the living room, and also turn on the phone (the phone will aumatically weaken the screen background light), why are your eyes uncomfortable? Therefore, my guess is that the absolute blue light intensity will damage the eyes, but the relative background intensity will affect the human eyes.