To identify whether the anti-blue lens has anti-blue light function, there are 3 ways:
(1) Test method for spectrophotometer. This is a laboratory method, the equipment is expensive, heavy and difficult to carry, but the data is accurate, sufficient and quantitative. This method is not possible in general retail stores, but there is an alternative method, which is to use the "portable Blu-ray instrument" produced by Shenyang Shangshan Medical Devices Co., Ltd. to measure the transmittance of ultraviolet light and blue light. This method is a multi-point wavelength weighted average test. , can test its comprehensive blue value, but no wavelength test value.
(2) Tested with a Blu-ray pen on the market. This method is low in cost and convenient to test, and can be used for terminal display, but has the following three problems: First, the blue light emitted by the blue pen on the market is about 405 nm, and the bandwidth is about 10 nm. It belongs to blue-violet light. Relatively speaking, the light source of this wavelength is also better to find some. If you want a blue light source with a center wavelength of 430nm, you need a relatively special filter, and the price of the pen will go up. Second, the single point wavelength test is not enough for us. Third, we should also pay attention to the specific transmittance of each wavelength point, rather than a qualitative data. In general, the use of the Blu-ray pen method is a last resort, you can choose a reference.
(3) Use the self-declaration of the company. At this time, we must believe in the power of the brand, I believe that most lens manufacturers will not falsify the quality and efficacy of the product. For consumers, we can also use the same concept. For example, we say to customers: “This brand is an international (domestic) famous brand. We have been selling for a long time, and the user has a good reputation. You can rest assured; this is provided by the brand. The product inspection report is issued by the national authority and there will be no problem."
Regarding the second question, the answer is already very obvious. The reason why the blue pens provided by different manufacturers test the same lens is different, because the spectral range of each blue pen is different, only the 435±20 nm blue pen can be tested. Anti-blue lens effect.