How to choose sunglasses to avoid hurting your eyes in summer

Summer is here, and probably everyone has sunglasses. Today I would like to talk about sunglasses. I found that some people wear them and some don't. So is it good to wear them in summer? Is it necessary to wear sunglasses? I can tell you for sure that you must wear sunglasses, especially when the sun is strong. This is not just for beauty or 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?

The most important function of sunglasses is to block strong light and prevent harmful light such as ultraviolet rays from entering the human eyes too much and causing damage. If you wear sunglasses in the summer, first, it can reduce the adjustment burden of the ciliary muscles of the eyes under strong light, allowing the eyes to see objects under the accustomed 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 eyes in windy weather, which, to a certain extent, becomes the best safe haven for the eyes. According to relevant experts, sunspot activity has become more and more frequent since 1996, causing increasing damage to the human body caused by ultraviolet rays. This is especially true in plateau areas such as Qinghai and Tibet in my country, where people are most susceptible to damage from ultraviolet rays due to the long sunshine hours. Therefore, people living in these areas should especially wear sunglasses.

Gray, green and brown sunglasses are best for your eyes

2. Which color of sunglasses is best for your eyes?

In the earliest times, there was only one kind of sunglasses with large frames and large lenses. Because they looked like the eyes of a frog, people at that time also called them frog glasses. They were round and came in only one color, black. Now it is different. We have several types, such as wide-rimmed, narrow-rimmed, square, round, long, and slanted. There are also more colors, such as red, green, yellow, and amber, which make people dizzy. Now there are more than 20 kinds. With more choices, it is difficult to make an idea. However, not all colors are good for the eyes. In addition, the sunglasses you like may not be suitable for you when you wear them. Let’s talk about the color of sunglasses first.

The production materials of sun lenses on the market are basically the same as those of myopia lenses, and they are also divided into two categories: glass lenses and resin lenses. However, the processing techniques of the two are different. Sunglasses with glass lenses are mainly made by mixing some metal salts with special absorption properties into the glass material. For example, glass lenses with nickel and cobalt are purple, and glass lenses with cobalt and copper are blue. Sunglasses with resin lenses are mainly made by immersion dyeing, which is to immerse the lenses in hot water dissolved in organic pigments for coloring. However, no matter which coloring method is used, the color of the sunglasses must be beneficial to our eyes. So, facing so many colors of sunglasses on the market, which one should we choose?

Expert: From a human physiological perspective, gray, green, and brown are good for the human eye, while colors that are too dark or too light are not good.

Sunglasses that are too dark in color may cause traffic accidents due to poor traffic sign recognition ability, while sunglasses that are too light in color cannot block the sunlight. my country currently only has strict regulations on the traffic sign recognition ability of red, green and yellow sunglasses. There are no relevant regulations for other colors, but here is a trick you may want to try when choosing sunglasses: that is, you must try them on when buying to see how much color difference changes in the surrounding environment. Generally speaking, sunglasses with small color difference changes are more suitable in color.

3. Which material of lens has better UV protection effect?

Many people believe that the darker the color of the sunglasses lens, the more UV protection it has. In fact, whether sunglasses are UV-proof or not has nothing to do with the color of the lens, but is related to the production material of the lens. If UV-proof materials are added to the sunglasses during production, then they are sunglasses with UV protection function. Such sunglasses are generally sold with UV logo, but due to the limitations of current processing technology, the UV protection function of sunglasses can only reach 97% at most, and it cannot reach 100% at all. So when you see sunglasses with the UV100% logo, it is actually not living up to its name.

To determine whether sunglasses are UV-proof, in addition to checking whether they have UV labels, you can also check whether the edges of the lenses connecting to the frame are smooth. Lenses with smooth edges are made of resin materials, which have stronger UV protection capabilities. Lenses with wavy edges are generally made of glass materials, which not only have poor UV protection capabilities, but are also prone to produce degrees during installation, which is harmful to our eyes.

4. Can I only wear sunglasses in summer?

Of course not. The main function of sunglasses is to block strong light. So, in fact, after a heavy snow in winter, you'd better wear sunglasses to block the glare and protect your eyes.

5. Can you trust the sunglasses sold at roadside stalls?

It is not credible. The quality of sunglasses sold at roadside stalls cannot be guaranteed because the lenses of such sunglasses are likely to be made of plastic. Plastic is very cheap and not only can it block ultraviolet rays, but also has poor light transmission. Therefore, you must not buy sunglasses for your children from roadside stalls.

6. Are large-frame sunglasses good?

Of course it is not good, because the infraorbital edge of the large-frame sunglasses will press on the exit of the infraorbital nerve when worn. As the wearing time increases, symptoms such as local skin numbness, dullness, and visual fatigue will appear around the eyes. Therefore, it is recommended that you choose sunglasses with small frames.

7. Can wearing sunglasses really protect the skin around the eyes from spots?

This is not necessarily the case. Whether spots appear on the skin around the eyes is not only related to ultraviolet rays, but also closely related to the human body's endocrine system. So 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 protect the eyes?

This statement is inappropriate. Because crystal is hard, has good heat insulation, and feels cool when worn, it is known as a good product for eyesight. However, crystal lenses can transmit more than 80% of ultraviolet rays, and ultraviolet rays are harmful to human eyes. When the eyes absorb too much ultraviolet rays, the lens will become cloudy, thus affecting vision. According to international standards, the long-wave ultraviolet rays UVA that are allowed to pass through the lenses should be less than 10%, while medium-wave ultraviolet rays UVB should not be allowed to pass through, otherwise it will cause damage to the eyes. However, crystal lenses can transmit about 90% of long-wave ultraviolet rays UVA and about 90% of medium-wave ultraviolet rays UVB. Therefore, if the advantage of eye care is compared with the disadvantage of ultraviolet damage, it is really not worth the loss. Ordinary optical lenses, high-refractive glass lenses, coated lenses, etc. all have the function of absorbing and intercepting ultraviolet rays. In comparison, the optical properties of crystal glasses are far inferior to ordinary optical glass. In addition, crystal is quartz crystal, which contains many irregular impurities and cotton-like ripples inside. It is an inhomogeneous medium and has birefringence, which forms a double image after refraction of light, causing unclear vision. Therefore, neither natural crystal nor artificial crystal is suitable for making glasses.