To prove that not all blue light is harmful

Is blue light all bad? Must wear blue eyeglasses online cheap for protection?

To figure this out, you need to know what blue light is. Blue light refers to light with a wavelength between 400 and 500 nanometers, which is ubiquitous in People's Daily life. All kinds of energy-saving lamps, LED lamps and incandescent lamps, as well as daily contact with sunlight, bath, flat panel displays, fluorescent lamps, liquid crystal displays, mobile phone screens and other new artificial light sources emitted in the visible light contain blue light.

In recent years, it has been widely spread in society that blue light can cause photochemical damage to the retina, leading to macular degeneration of the retina, and even blindness. In this regard, CAI Jianqi, director of the Visual health and safety protection Laboratory of the China Institute of Standardization, said in an interview with reporters that blue light should also be treated differently and cannot be "one-size-fits-all".

"According to our experiments, blue light below 445 nanometers is very low tolerance to the retina of the human eye. That means effective protection is needed." CAI Jianqi said that for blue light below 445 nm, under normal circumstances, anti-blue light products are needed to help shield 20% of the energy. In other words, consumers can choose anti-blue light glasses with a transmission ratio of less than 80%.

For blue light above 445 nm, the human eye tolerance shows a geometric increase, that is, the human eye tolerance is extremely high. CAI Jianqi said that in daily life, whether it is the LED lighting products used or the LED display, the blue light radiation energy is basically between 450 nm and 470 nm, avoiding the most vulnerable area of the human eye. Under normal use, the blue light emitted by electronic products will not cause blue light harm to the human eye.

There is also a part of blue light, which does not need shielding and is essential to the human body. CAI Jianqi further explained that 450 to 480 nanometers of blue light, can play an effective role in regulating the body's biological clock, that is, regulating the human physiological rhythm. If this part of the blue light is also blocked out, it is not only good for the human body, but also harmful.

Standard, blue blocking glasses must block at least 20% blue light

The reporter's inquiry found that as early as the end of 2017, Guangdong Province had issued a local standard "Blue light transmission requirements and test methods for anti-blue eye lenses and related glasses products", which became the first local standard for anti-blue eye lenses in China.

At the beginning of this year, the State Administration for Market Regulation also issued an action plan to implement the Implementation Plan for Comprehensive Prevention and Control of Myopia in Children and Adolescents. It is clearly proposed that electronic products, including mobile phones, ipads, computers and other products of blue light and other electromagnetic radiation on the impact of young people's vision, to carry out comparative tests, including the claim of anti-blue light mobile phone film products to test, compare the blue light before and after the film, to provide a reference for consumer choice.

"The national standard for anti-blue light glasses has been submitted for approval and is expected to be released before the end of this year, and may be formally implemented next year." As one of the main drafters of this national standard, CAI Jianqi told reporters that in the standard called "Technical requirements for light health and light safety application of Blue protective film", it is clearly proposed that for blue light below 445 nm, the light transmission ratio of anti-blue glasses is less than 80%, that is to say, anti-blue glasses need to help the wearer shield 20% of the blue light energy. For blue light above 445 nanometers, the light transmission ratio of anti-blue glasses is higher than 80%.

This also means that if the light transmission ratio of the eye lens does not meet the standard requirements, it can not claim to be "anti-blue light glasses".