Can Blue LEDs Enter The Classroom

- Jul 17, 2019-

Students are better off reading in natural light, and the natural spectrum is seven colors. Nowadays, when the eye of love is coming, the use of light source for classroom auxiliary lighting in Guangzhou has attracted some experts' attention. I used to work at Harvard Medical School in the United States and is currently a professor at Zhongshan University College of Science and Technology. Professor Zhou Wenliang, a doctoral tutor, said, "If you want to use auxiliary light sources, most of the LED lights in the market are too strong. From the perspective of protecting young people's eyes, I personally do not advocate using them in the classroom. ”


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Newly modified three-color light source classroom


Students are better off using natural light


“Students are better off using natural light,” said Mai Jincheng, a member of the National Health Policy Committee’s School Health Standards Committee. Natural sunlight is a seven-color light, and the light source that is close to the sun is the safest. “But, in terms of specific use, At the end of the school classroom and at the end of the classroom wall, the natural light is very different, which requires a reasonable auxiliary light source to be installed in the classroom."


From the health education position of the education department in Guangzhou, Mai Jincheng has been working on classroom design for ten years. He believes that the light source closest to the spectrum of sunlight is the most suitable illumination source for classrooms.


Student classroom auxiliary light source attracts expert attention


So, what classroom auxiliary light source is better?


According to Mai Jincheng, member of the School Health Standards Committee of the National Health and Family Planning Committee, the current standards related to school classroom lighting are:


(1) GB7793-2010 "Standards for Lighting and Lighting Hygiene of Primary and Secondary School Classrooms" Article 5.5 "Classroom adopts small-diameter straight-tube type rare earth trichromatic fluorescent lamps of less than 26mm"; (2) GB50034-2013 "Architectural Lighting Design Standards", Section 3.2. 2 "Small tube straight-tube type three-color fluorescent lamps should be used in the room with low installation height of lamps"; (3) JGJ310-2013 "Electrical Design Code for Educational Buildings" Article 8.4.3 "Reading room, library, classroom, meeting room For offices, etc., it is advisable to use a small-diameter three-color straight tube fluorescent lamp."


With the development of LEDs in emerging industries, some schools in Guangzhou have begun to use LEDs as auxiliary light sources to enter classrooms, playgrounds and other venues, which has attracted the attention of experts such as Mai Jincheng and Zhou Wenliang.


Among them, recently, Professor Zhou Wenliang of the Zhongshan University of Science and Technology has just completed a review article on the visual hazard and non-visual influence of white LEDs, and proposed some new ideas even in the international arena.


Professor reminds the classroom with LED


Professor Zhou Wenliang: "It should be said that the white LEDs used in the color temperature range defined by the national standards in strict accordance with national standards are safe for adults. The rapid development of white LEDs in the past few years has strongly promoted semiconductors. The development of the lighting industry. But white LED is only one of the semiconductor lighting, has outstanding advantages, is good for general indoor lighting. But for children and adolescents, the risk exists, especially in the long period of student retention. Used in the classroom."


Professor Zhou Wenliang believes that the LEDs currently used in the market are all white LEDs. The yellow phosphors are used to stimulate the yellow phosphors and combine to form white light. This is the way to obtain white light at the lowest cost and is widely used.


However, it also has disadvantages. Due to the use of blue light pumping, it is inevitable that it will contain excessive blue light components, and the higher the color temperature, the more. Recently, although the country has issued some standards for LED blue light hazards, these standards are for adults and may not be suitable for young children.


Excessive blue light may cause retinal damage


Zhou Wenliang said that excessive blue light may cause confusion of retinal damage and human birth rhythm.


“It is impossible to use humans to do experiments at present”, Professor Zhou revealed, and some animal experiments found that white LEDs with low illumination and low color temperature are not absolutely safe. Therefore, the current controversy of LED lights is relatively large. From the perspective of protecting students' health, I personally do not advocate application in the classroom. “Teaching outdoor playgrounds, aisles, etc. can be illuminated with LEDs.”


How can I prevent teenage myopia?


According to Mai Jincheng, studies abroad have shown that teenagers who spend three hours a day outdoors can reduce their chances of having myopia by 30% than those who are not outdoors for three hours.


“Adolescents’ three-hour outdoor activities may not be realistic any day.” Mai Jincheng suggested that each school should preferably organize students to engage in one-hour outdoor activities every day to reduce the proportion of young people suffering from myopia.