What is the uv protection computer glasses?
The sun give off light has: visible light, infrared, ultraviolet and other three. With ultraviolet radiation to human body skin and eyes. In the. Cause serious damage, such as, Released by the sun light is divided into UVA, UVB and UVC, if long time exposure can cause damage to the body, UVB has a serious effect on vision, yellow glasses for computer is burned black light, most of the canthus can absorb the UVB light so be sure to block out the light.
Uv protection computer glasses because has the function of the polarization of light, so will all the harmful rays of blocking off does not affect the visible light through, can truly achieve the purpose of protecting our eyes. if you want to buy computer glasses Philippines, you can choose us.
What kind of glasses to uv?
Avoid light radiation damage to the eyes, the most effective and the most commonly used method is to wear safety glasses. The so-called protective glasses is a kind of filter, can change through the light intensity and spectrum.
The computer glasses is divided into two major categories, one for absorption, one for reflection type, the former is used most frequently.
The computer screen reading glasses lens in the manufacturing, in the general formula of optical glass and add the part of metal oxides, such as iron, drill, strontium, nickel, chromium, manganese and some rare earth metal oxides such as neodymium and etc.
The metal oxide can make glass to light some wavelengths of electromagnetic waves in the selective absorption, such as cerium and iron oxide can absorb a large number of ultraviolet light. Use this computer eyewear lenses can reduce the amount of certain wavelength through the computer eyeglasses lens, reduce or prevent damage eyes.
One, the absorption filter
Also known as sunglasses. About 20% of visible light transmittance, better absorption of prescription glasses for computer work ultraviolet and infrared light. There is light green, light gray, a variety of colors, such as weak tea used to create shading and snow job safety glasses or computer reading glasses.
The light grey lens to identify the minimal impact of color; Shallow tea glasses looks darker blue sky, green light by decreasing; Light green lens cut through the red light is.
Second, the reflection type filter
Absorption filter, eye protection glasses from computer is to use the lens to absorb certain wavelengths of light, in order to reduce the light into the eye, but because the lens absorbs some light, heat rejection, especially longer light, infrared and other wave due to the accumulation of heat, computer eyeglasses make the eyes feel uncomfortable.
Actual working life, in many cases is the absorption and reflection type combined use, namely to a high reflection film plated on the colored lenses, the filter effect is stronger, chlorine, such as welding, arc welding, plasma cutting, such as operating personnel to wear computer glasses, this kind of method can be adopted to solve.
Small make up remind:
In the store had found that the lens price difference is quite big, according to salesperson introduction, the lens in the membrane can prevent computer radiation, uv protection, this statement computer screen glasses is not correct!
Coating effect has been exaggerated, coating has the effect of uv and prevent computer radiation, belong to out of thin air. Because general lens has anti-radiation effect, and uv protection is required in the lenses with special material, which has nothing to do with the coating.
Good quality computer screen reading glasses lens coating, the price is almost the same as the lens. If there is a store had said to add layer coating is only more than 10 dollars, that is about to consider the authenticity and quality problem. But the film after, look from flank the lens appears purple or blue, show that coating only block which color of light, there is no difference in quality.
How to judge whether a uv protection sunglasses?
Methods 1. See sunglasses tags
Sunglasses ultraviolet prevention function, the express way generally have the following kinds:
A) labeled “UV400” : this means that the lens of uv cutoff wavelength of 400 nm, namely its (lambda) under 400 nm wavelength in the maximum of the spectral transmittance of tau Max (lambda) is not greater than 2%;
B) marked with “UV” and “anti ultraviolet” : this says the lens of UV cutoff wavelength of 380 nm, namely its (lambda) under 380 nm wavelength in the maximum of the spectral transmittance of tau Max (lambda) is not greater than 2%;
C) labeled “100% UV absorption” : this means that the function of the prescription glasses for computer work lens is 100% for UV absorption, namely in the UV range of average transmission ratio is not greater than 0.5%.
To achieve the above requirements of sunglasses, is in the true sense of uv protection function of computer sunglasses.
Methods 2. Use money + yanchao pen to verify
In the absence of the instrument, ordinary people also can detect whether the sunglasses have uv protection function.
Take a piece of money, put the computer glasses lenses on the anti-counterfeiting watermark, illuminates with UV ray pen or counterfeit detector in the lens. If you still can see the watermark is this pair of sunglasses is not uv protection, if not see, is this pair of sunglasses for uv protection.