Fu Yanjiang, director of the Department of Ophthalmology, Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, told reporters that Yuba’s eye is caused by blue light. Blue light does not refer to blue light, but high-energy visible light with a wavelength of 400-500 nm. It can penetrate the lens to reach the retina, causing optical damage and accelerating the oxidation of cells in the macula. Therefore, blue light has been confirmed to be the most harmful visible light.
Infants and young children are the most vulnerable to blue light damage. Because the lens at birth is relatively clear, it is difficult to filter blue light. In the age range of 0-2 years old, about 70-80% of blue light can penetrate the lens to reach the retina. At the age of 2-10 years, about 60-70% of blue light will hit the retina. Therefore, when treating neonatal jaundice with blue light, the doctor must cover the baby's eyes with black cloth to avoid injury.
The damage of the blue light to the eyes is gradually formed. Even if the child does not look directly at the light source, it will cause damage to the eyes for a long time. Therefore, for children, especially those who like to "find bright", it is very important to protect your eyes from blue light. What other light sources have blue light?
LED lighting. For example, the light of a computer screen, an iPad, a big screen mobile phone, and the like. The light of the iPad is the most eye-catching.
The flashing light of the toy. Many children's toys have a constantly flashing light source. Although the intensity is not large, the children are more likely to cause damage.
flash. Take pictures of children under 2 years old, preferably without using a flash.
Spotlights. For families with children, stage lighting should be used less to protect the child's eyes.
According to GB/T 20145-2006 blue retinal hazard can be classified as:
1) No danger (radiation ≤ 100 W·m-2·sr-1): The scientific basis of the non-hazard class is that the lamp does not pose any photobiological hazard under the extreme conditions of this standard;
2) Low risk (Class 1) (radiance ≤ 1 × 104 W·m-2·sr-1): The lamp does not pose a hazard under the normal exposure conditions;
3) Danger (Class 2) (radiance ≤ 4 × 106 W · m - 2 · sr-1): The light produced by the lamp does not cause the danger of glare and temperature discomfort.
4) High risk (Category 3) (radiance > 4 × 106 W · m - 2 · sr-1): The lamp causes harm in a shorter moment.
2. Corresponding judgment requirements
According to IECEE CTL Resolution DSH 0744:
1) When the brightness is less than 10000 cd/m2 and only visible light is emitted, it is not necessary to classify the hazard class according to GB/T 20145-2006. It can be classified as non-hazardous and can be used directly. If the brightness is greater than 10000 cd/m2, it should be treated as described in 2) or 3) below.
2) If the manufacturer provides a test report indicating that the radiance of the luminaire does not exceed the non-hazardous category and low risk (Class 1) specified in GB/T 20145-2006, the certification body may accept such LED luminaires and consider it to be normal. There is no photobiological hazard in the case.
3) If the manufacturer does not provide such a claim, it should be tested in accordance with GB/T 20145-2006, and the test results meet the requirements of 2) above.
3. Marking requirements for products of category 2 and above
According to the draft of IEC 62471-2 and IEC 60598-1 8th edition, LED light sources and LED lamps of Class 2 and above have no warning signs and cannot be used directly.