| Launch：2022-05-26 |
abstract
The transmittance measurement system is built with xsm11639 optical fiber spectrometer, dh2000 deuterium halogen integrated light source and qp600 quartz fiber, which can measure the full band transmittance of the lens and evaluate the quality of the lens.
Research background
In recent years, there have been many blue light proof flat lenses and myopia glasses on the market. Businessmen publicize that wearing it is like having a "amulet", which can resist all harmful blue light emitted from the electronic screen, prevent myopia and fatigue, and "see far clearly and see near comfortably". Therefore, many white-collar workers, their mothers are willing to spend more money to buy such a guarantee. Can the anti blue light lens effectively resist the blue light as the merchant said? Why on earth should we prevent blue light? Before talking about this problem, let's popularize relevant knowledge.
01. What is Blu ray?
When it comes to blue light, let's first understand the knowledge of visible light. Visible light is the part that can be perceived by human eyes. Generally, the wavelength is between 400 ~ 760nm, and blue light is an important part of visible light. The wavelength is between 380-500nm. We often feel that blue light with short wavelength and high energy is dazzling. In addition to the sunlight in nature, the display screens of mobile phones, computers and other electronic products contain blue light. At the same time, in order to make the electronic screen whiter and brighter, a large amount of blue light is retained in the background light (artificial light source) of many led, computer and other electronic products.
02. Why prevent blue light?
Blue light can be divided into beneficial blue light and harmful blue light. Blue light with a wavelength of 480 ~ 500nm can regulate the body's biological clock, maintain daytime vision, improve mood and memory, and ensure our normal visual function. The wavelength of harmful blue light is between 385-445nm. Because the light wave is relatively short and the energy is relatively large, the tolerance of visual cells to high-intensity short wave blue light is low and prone to damage. High energy blue light has strong penetration and can penetrate the lens directly to the retina. Excessive high-energy blue light will also cause the atrophy or even death of retinal pigment epithelial cells, and eventually lead to the decline or even complete loss of vision. This damage is irreversible.
03. Lens inspection test
In view of the many hazards of Blu ray, Xiao Bian was so frightened that he quickly took out his glasses and tested them. He also took my colleague Xiao Ming's myopia glasses and Lao Wang's professional anti Blu ray glasses.
The transmittance spectra of the three glasses are shown in the figure below. It can be seen from the figure that Lao Wang's professional anti blue light glasses effectively filter out the 380-440nm blue light band, which really has the effect of anti blue light. Xiaoming's ordinary myopia glasses have no anti blue light function, and there is no filtering for the blue light base of the same frequency band. Cough, the so-called anti blue light glasses bought in the small editing live broadcast room only prevent some blue light, and the protective effect above 420nm is basically gone.
l Knock on the blackboard - here's the point
With regard to blue light protection, the national standard GB / t38120-2019 technical requirements for light health and light safety application of blue light protective film was officially implemented in July 2020, which clearly stipulates the standard of blue light protective film for anti blue light optical lens products. In the range of 415-445nm, the light transmittance should be less than or equal to 80%. More than 80% above 445nm.
The equipment used in this measurement can simply and quickly test the spectral transmittance of the lens, which can be convenient for the majority of lens manufacturers, professional evaluation personnel, quality inspection institutions, scientific researchers and other research and use, and can easily and effectively detect whether the sample is "qualified".
04. Test recommended configuration
1. Xsm11639 optical fiber spectrometer
2. Dh2000 deuterium halogen integrated light source
3. Qp600 quartz optical fiber
4. Measuring bracket
