2. Avoiding strong light from guns can reduce the adjustment burden of ciliary muscles of eyes under strong light, so that people can see objects in natural light.
3. In windy weather, it can also prevent dust particles from entering people's eyes.
Choose sunglasses. At present, there are some myopia sunglasses with degrees on the market, but because the pupil distance and other indicators vary from person to person, it is best for consumers not to choose these sunglasses with degrees without the guidance of professionals.
2. first, observe whether the lens has scratches, impurities, bubbles and stripes, and check the outer packaging of sunglasses. Regular sunglasses should be marked with product name, color, diameter, quality grade, manufacturer name and trademark, and sunglasses with anti-UVA, UVB and CE signs on the mirror or tag can ensure that certain ultraviolet rays are blocked.
3. Hold the two corners of sunglasses against the fluorescent lamp by hand, and let the reflective strip of the mirror surface roll gently. If the fluorescent lamp shadow reflected by the mirror surface appears wavy and twisted, it proves that the lens is uneven, and such a mirror surface will damage the eyesight.
4. The lenses should be flat and transparent. The materials of sunglasses are glass and resin, and the best sunglasses should be polarized lenses. It is made of synthetic resin as light and precise as contact lenses, and is composed of seven thin layers, and the outermost two layers are superhard wear-resistant layers; The second and sixth layers are shatterproof strengthening layers; The third and fifth layers are ultraviolet filter layers, and the middle layer is polarized filter layer. Polarizing lenses can effectively filter reflected light and harmful ultraviolet rays, and have the functions of shatterproof and abrasion resistance, and are the most popular sunglasses.
5. The color of sunglasses should be matched according to your skin color, face shape and wearing, and also according to the place where you go in and out. Generally speaking, black, brown and gray have good filtering effects; Gray lenses can absorb any color spectrum evenly, and the scenery you see after wearing them will only darken without obvious color difference; Brown lenses can filter out a lot of blue light, which can improve visual contrast and clarity, especially when the air pollution is serious or foggy.
6. Generally, regular optical shops will have instruments to test the ultraviolet resistance of sunglasses. Through this test, you can know whether the glasses in your hand are helpful to your eye health.
7. In addition to reducing the strong light stimulation and making eyes comfortable, the main purpose of wearing sunglasses is to prevent ultraviolet rays from harming eyes. The color of lenses and whether they are protected from ultraviolet rays are two different things. Even if the lenses are dark in color, they may not be effectively protected from ultraviolet rays. Therefore, you must choose lenses marked with anti-UV functions. Usually, the UV index of sunglasses is between 96% and 98%.
8. The shades of sunglasses are limited to the fact that you can vaguely see your own pupil. If the color is too light, the filtering effect is too small; If the color is too dark, it will affect the vision and weaken the color sense. This year's popular colorful and light-colored sunglasses should not be used in seaside water activities, snow with strong reflection or under the sun with strong sunshine, but should be worn with sports sunglasses, most of which are colorful and saturated colors, which can absorb or reflect more visible light.