Fu Yanjiang, director of the ophthalmology department of Beijing Hospital of Traditional Chinese Medicine affiliated to Capital Medical University, told reporters that the bath bomb hurt his eyes because of the blue light in it. Blue light does not refer to blue light, but high-energy visible light with a wavelength of 400-500 nanometers. It can penetrate the lens to reach the retina, causing optical damage and accelerating the oxidation of macular cells. Therefore, blue light has been confirmed by research to be the most harmful visible light.
Infancy is the period when the eyes are most vulnerable to blue light. Because the lens of the baby is relatively clear at birth, it is difficult to filter blue light. In the age group of 0-2 years, about 70-80% of blue light can penetrate the lens to reach the retina, and in the age group of 2-10 years, about 60-70% of blue light will irradiate the retina. Therefore, when treating neonatal jaundice with blue light, the doctor must cover the baby's eyes with a black cloth to avoid injury.
Blue light damage to the eye is formed by gradual accumulation. Even if the child does not look directly at the light source, it will cause damage to the eyes over time. Therefore, for children, especially small babies who like to "find light", it is very important to protect their eyes daily from blue light damage. What other light sources have blue light?
LED lights. For example, the light of computer screens, iPads, large-screen mobile phones, etc. Among them, the light of the iPad hurts the eyes the most.
The twinkling light of the toy. Many toddler toys have a constantly flickering light source, although the intensity is not large, but the child is exposed to more, and it is easy to cause injury.
Flash. Take pictures of children under 2 years old, preferably without flash.
Spotlights. Families with children should use less spotlights with stage effects when decorating to protect children's eyes.
According to GB/T 20145-2006, blue retinal hazards can be classified as:
1) No danger (radiation brightness ≤ 100 W·m-2·sr-1): The scientific basis of the non-hazard class is that the lamp does not cause any photobiological hazard under the limit conditions of this standard;
2) Low hazard (Class 1) (radial brightness ≤1×104 W·m-2·sr-1): Under normal exposure conditions, the lamp does not produce danger;
3) Medium hazard (Class 2) (radial brightness ≤4×106W·m-2·sr-1): The kind of danger that the light produced by the lamp does not cause people to feel strong light and temperature discomfort.
4) High hazard (Class 3) (spoke brightness >4×106W·m-2·sr-1): The lamp causes harm in a shorter instant.
2. Corresponding judgment requirements
According to IECEE CTL Resolution DSH 0744:
1) When the brightness is less than 10000cd/m2, and only visible light is emitted, there is no need to classify the hazard level according to GB/T 20145-2006, which can be classified as no hazard level and can be used directly. If the brightness is greater than 10000cd/m2, it should be treated according to the method of 2) or 3) below.
2) If the manufacturer provides a test report indicating that the radial brightness of the lamp does not exceed the no-hazard class and low-hazard (Class 20145) specified in GB/T 2006-1, the certification body can accept such LED lamp and consider that it will not produce photobiological hazards under normal circumstances.
3) If the manufacturer does not provide such a claim, the test should be carried out according to GB/T 20145-2006, and the test results meet the requirements of the above 2).
3. Marking regulations for products of Class 2 and above
According to the draft of IEC 62471-2 and IEC 60598-1 8th edition, LED light sources and LED luminaires of category 2 and above cannot be used directly without warning markings.