How to choose and buy sunglasses products
Domestic sunglasses, although the brand is numerous, but few consumers can call on the name brand. In contrast, many consumers while not choose imported brand sunglasses, but a thing of some famous brand, and to many domestic brands, know not many people. When a lot of consumer is buying sunglasses, there is no too care about the brand, just think wearing suits oneself bought it, cost also is generally not high. Domestic sunglasses not attaches importance to its propaganda, though there are some material, big can cost thousands of yuan, the domestic general also hundreds of yuan, sold the work again. And domestic brands on the design effort, more is imitation, no element into his own personality. Thus cause a lot of attention to the brand and the quality of consumers more choice of international famous brands. That we how to choose the sunglasses? According to choose sunglasses ultraviolet prevention signs: sunglasses antiglare chord is the main purpose of the light, uv radiation, in particular, in the summer protect eye health. Therefore, simply speaking, it is important to note that when buy lens and packaging on the presence of 'UV400' and 'uv' logo, logo. According to QB2457 - 1999 the requirement to sign, each pair of glasses shall indicate the execution of the standard code ( QB2457, etc. ) And category ( Shading mirror or light color sunglasses, etc. ) And the production factory name and trademark. Categories marked for consumers in choosing sunglasses elbow can be conducted according to the purpose and correct choose and buy. A pair of sunglasses, with our current standards does not necessarily have anti ultraviolet or shock, such as additional protection performance, only when the products have clear performance, will these indicators appraised: one, the logo uv ultraviolet prevention function refers to the wavelength of 100 nm to 380 nm of the sun's rays, including three categories: UVA wavelengths of 315 nm - 380 nm, UVB rays wavelength of 280 nm to 315 nm, UVC wavelength of 100 nm to 280 nm. The sun's rays reaching the earth's surface ( 290 nm～2000nm) In the ultraviolet (uv) accounted for about 13%, and more than 97% UVA, UVB accounted for 3%, UVC close to O. Uv damage to the human eye is mainly depends on the wavelength of ultraviolet radiation, radiation time and strength, the strength of the defense mechanism, the human eye and cornea, lens is often the uv damage the eye tissues, sunlight keratitis cataract and corneal endothelial injury, sun is associated with eye diseases. In order to protect the health of the eye, can choose the sunglasses with uv resistant, as far as possible eliminate under 380 nm uv light. When the choose and buy should pay special attention to glass lenses ultraviolet prevention function, from the spot check statistics, glass is hard to fully meet the requirements of anti ultraviolet. Second, the relevant safety identification with safety protection performance of sunglasses, its lens USES such as PC pieces and impact resistant material is made, on the label and tend to be marked on the manual 'shock resistance', 'through the FDA certification', 'conforms to the European and American standards', etc. , if the product can meet the requirements of logo on, for motorcyclists, drivers, etc have special requirements on safety performance of consumers is a good choice. Many people mistakenly believe that the depth of the lens color is proportional to the uv protection performance, the fact is that the lens color depth refers to the transmittance of visible light, only you can judge with the naked eye, and the ultraviolet ray is visible to the naked eye cannot be observed, the lens uv protection performance can only be detected by ultraviolet spectrum analyzer. A simple method to test the uv protection is: take a one hundred - yuan renminbi notes of fluorescent light zone, after turn on the light switch, the patterns of the yuan in light yellow, according to clear. At this time the sun glasses again on the renminbi, pattern due to ultraviolet radiation is blocked immediately disappear, this suggests that the sunglasses have the ability to block ultraviolet light. If the pattern in the reflex zone has not disappeared, suggesting the sunglasses without uv protection function, such as sunglasses is unqualified, can't buy.