The advancement of technology has led to the continuous emergence of various lighting sources, which not only enrich lighting products and meet people’s usage needs, but also pose harm to humans due to improper use. The harm of blue light has been causing significant reactions in the lighting industry since its first exposure. Recently, some medical experts have expressed concerns that LED blue light may cause damage to the retina, and even blindness. This news has attracted widespread attention and a large number of reposts and comments from netizens online, as well as high attention from lighting experts.
Blue light “refers to the part of visible light that is closest to ultraviolet light. These wavelengths in the range of 400-500 nanometers have slightly lower frequencies than ultraviolet light and are the most energetic part of visible light. The colors are blue and purple, hence they are commonly known as” blue light “.
The so-called blue light hazard refers to the harm that blue light radiation can cause to the human eye in a short period of time or instant when it reaches the standard of Class 2 or Class 3. The standard it is based on is GB/T 20145-2006/CIE S009/E: 2002, and the judgment is based on CTL-0744-2009-laser resolution.

The human eye has approximately 120 million columnar cells and 8 million pyramidal cells. Visual cells cannot be regenerated after death, therefore, the visual cells of the human eye are the most precious and non renewable resource of the human body. Columnar cells can only sense the brightness and darkness of light, while cone cells produce bright vision under normal illumination (with a brightness value greater than 3CD per square meter). Cone cells sense the color of light.
Cone shaped cells are divided into three types: cone shaped cells that sense red light, cone shaped cells that sense green light, and cone shaped cells that sense blue light. Cone shaped cells that sense red light are most sensitive to wavelengths of 650-680nm, cone shaped cells that sense green light are most sensitive to wavelengths of 560-570nm, and cone shaped cells that sense blue light are most sensitive to wavelengths of 440-450nm. This is similar to the emission wavelength of white LED chips, which is also the reason for the blue light hazard of LED lighting sources.
There is considerable controversy in the scientific community regarding the hazards of LED blue light. One of the viewpoints is consistent with the views of medical experts mentioned earlier. There are two visual channels for light to enter the human eye, one is the imaging visual channel, and the other is the non imaging visual channel for biological clock and time. They believe that the blue light from LED lamps may cause visual harm to the retina in the imaging visual channel. On non imaging channels, the blue light from LED fixtures may affect the circadian rhythm.
At present, most of the lighting LEDs on the market are white LEDs, which stimulate yellow fluorescent powder through blue light chips and combine to form white light. Although this method obtains white light at the lowest cost, it inevitably contains excessive blue light components due to the use of blue light pumping, and the higher the color temperature, the more. Although the country has recently released some standards targeting the hazards of LED blue light, these standards are designed for adults and may not necessarily apply to children and adolescents.
Regarding the question of whether blue LED lights can enter classrooms, Professor Zhou Wenliang, who used to work at Harvard Medical School in the United States and is currently a doctoral supervisor at Sun Yat sen University, said, “If auxiliary light sources are used, most LED lights on the market currently have too strong blue light. From the perspective of protecting the eyes of young people, I personally do not recommend using them in classrooms for the time being.

The harm of blue light to the human body is still in the “early stages of research” – unlike the millions of patients who suffer from UV damage every year, evidence of the harm of blue light is mainly focused on experimental animals such as mice, rabbits, and monkeys. In this way, the harm of blue light to humans has not been confirmed, so standard blue light protection products will not be designed. However, as consumers, it is still necessary to have a comprehensive understanding of the hazards of LED blue light and take corresponding measures to prevent them for personal health reasons.