summer is coming. Maybe everyone has sunglasses. Today, let’s talk about sunglasses. It’s found that some people wear sunglasses and some don’t. is it good to wear sunglasses in summer? Is it necessary to wear sunglasses? Here we can definitely tell you that you must wear sunglasses, especially when the sun is strong, which is not only for beauty, decoration, wearing sunglasses has many benefits. The main function of sunglasses is to block strong light and ultraviolet rays
1. What is the main function of sunglasses?
one of the most important functions of sunglasses is to block strong light and avoid excessive harmful light such as ultraviolet rays from entering human eyes and causing damage. If you wear sunglasses in summer, first: it can reduce the adjustment burden of the ciliary muscles of the eyes under strong light and let the human eyes see objects under the habitual natural light, which is the most comfortable time for the human eyes. Second: wearing sunglasses is not only to block harmful light, but also to prevent sand and dust particles from entering the human eyes in windy weather, To a certain extent, it has become the best haven for the eyes. According to the measurement of relevant experts, since 1996, sunspot activities have become more and more frequent, resulting in greater and greater harm to human body by ultraviolet rays, especially in Qinghai, Tibet and other plateau areas in China. Due to the long sunshine time, it is most vulnerable to ultraviolet rays. Therefore, people living in these areas should especially wear sunglasses.
gray, green and Tan sunglasses are best for eyes
44555 2. Which color sunglasses are best for eyes?
in the early days, there was only one kind of sunglasses with large frame and large lens. Because it looked like two eyes of a toad, it was also called toad mirror at that time. It was round, and there was only one color, black. Now it is different. There are several kinds here, including wide edge, narrow edge, square, round, long and partial, There are also many colors, red, green, yellow and amber, which make the candidate’s eyes dazzled. Now there are more than 20 kinds. There is a big choice, but I don’t have an idea. But not all colors are good for the eyes. In addition, the sunglasses you like don’t necessarily suit you. Let’s talk about the color of sunglasses first.
at present, the production materials of solar lenses on the market are basically the same as those of myopia lenses, and they are also divided into two categories: glass sheet and resin sheet, but their processing processes are different. The sunglasses of glass lenses are mainly mixed with some metal salts with special absorption properties in the glass materials. For example, the glass lenses with nickel and cobalt are purple, The glass lens with cobalt and copper is blue, while the sunglasses with resin lens mainly adopt immersion dyeing method, that is, immersing the lens in hot water dissolved in organic pigment for coloring. However, no matter which coloring method, the color of sunglasses must be beneficial to our eyes. In the face of sunglasses with so many colors on the market, Which one should we choose?
expert: from the perspective of human physiology, gray, green and Tan are good for human eyes, and too deep and too shallow are not good.
Sunglasses with too dark color are likely to have traffic accidents due to poor traffic signal recognition ability, and sunglasses with too light color can not block the sun. At present, China has only made strict regulations on the traffic signal recognition ability of sunglasses with red, green and yellow colors, and there are no relevant regulations for other colors, but here is a trick, When you choose sunglasses, you might as well try them: that is, you must try them when you buy them to see the change of color difference in the surrounding environment. Generally speaking, the color of sunglasses with small color difference is more appropriate.
III. which material has better anti ultraviolet effect?
many people believe that the darker the color of sunglasses, the more UV resistant they are. In fact, whether sunglasses are UV resistant or not has nothing to do with the color of the mirror, but with the production materials of the lens. If UV resistant materials are added to sunglasses during production, they are sunglasses with UV resistant function, Such mirrors are generally sold with UV logo, but due to the limitations of the current processing technology, the UV protection function of sunglasses can reach 97% at most and 100% at all. Therefore, when you see Sunglasses with uv100% logo, it is actually not worthy of the name.
judge whether sunglasses are UV resistant. In addition to whether they have UV marks, you can also see whether the frame edge of the lens is smooth. The lens with smooth edge is made of resin material. This kind of lens has strong UV protection function. The lens with wavy edge is generally made of glass material. This kind of lens not only has poor UV protection function, It is also easy to produce degrees during installation, which is harmful to our eyes.
IV. can I wear sunglasses only in summer?
of course not. The main function of sunglasses is to block strong light. Therefore, in fact, after heavy snow in winter, you’d better bring sunglasses to block harsh strong light and protect your eyes.
v. are the sunglasses of roadside stalls credible?
is not credible. The quality of sunglasses on roadside stalls can not be guaranteed, because the lenses of such sunglasses are likely to be made of plastic. The cost of plastic is very low. It can not only prevent ultraviolet rays, but also have poor light transmission effect. Therefore, children should not buy Sunglasses on roadside stalls.
VI. how about big frame sunglasses? Of course,
is not good, because the infraorbital edge of the large frame sun hinge is just pressed on the outlet of the infraorbital nerve when wearing. With the extension of the mirror time, local skin numbness, retardation, visual fatigue and other symptoms will appear around the eyes. Therefore, it is recommended that you choose the small bar frame sunglasses.
VII. Can wearing sunglasses really protect the eye skin from spots?
this is not necessarily. Whether the skin around the eyes grows spots is not only related to ultraviolet rays, but also closely related to the human endocrine. Therefore, don’t think that wearing sunglasses can protect the skin around the eyes. In fact, wearing sunglasses only protects your eyes.
8. Can crystal glasses keep your eyes?
this statement is not appropriate. Because the crystal has a hard texture, good heat insulation and a sense of shade, it is known as a good product for nourishing the eyes. However, the crystal lens can pass through more than 80% of the ultraviolet light, which is harmful to people’s eyes. After the eyes absorb too much ultraviolet light, it will cause crystal turbidity and affect their eyesight. According to international standards, The UVA allowed to pass through glasses should be less than 10%, while UVB should not pass through, otherwise it will cause damage to the eyes. However, crystal lenses can pass through UVA by about 90% and UVB by about 90%. Therefore, if the advantages of nutrition are used to compare the disadvantages of UV damage, it is not worth the loss. Ordinary optical lenses High refractive glass lenses and coated lenses can absorb and intercept ultraviolet rays. In comparison, the optical properties of crystal glasses are far inferior to ordinary optical glass. In addition, the crystal is a quartz crystal, which contains irregular impurities and flocculent ripples. It is a non-uniform medium, and has birefringence, making the light form a double image after refraction, It causes unclear vision, so neither natural crystal nor artificial crystal is suitable for glasses.