Sunglasses can block ultraviolet rays because a special coating is added to the lenses. However, inferior sunglasses not only cannot block ultraviolet rays, but also seriously reduce the transmittance of the lenses, causing the pupils to enlarge. Instead, a large amount of ultraviolet rays will enter, causing eye damage. damage. Let's take a look at what you should pay attention to when buying sunglasses.
Sunglasses belong to the series of flat glasses. Good sunglasses should not only be able to block the sun, but also block the transmission of ultraviolet rays, have no diopter, and have good resolution ability for signal lights of different colors. Inferior sunglasses can cause symptoms of visual fatigue such as nausea, forgetfulness, and insomnia. The best colors for sunglasses are light gray, brown or light smoke, followed by green, amber, etc. Red is only used for sunbathing or on the snow. When choosing sunglasses, you should go to a regular optical store and choose sunglasses with UV protection produced by a regular manufacturer. It is best to avoid blue lenses and choose yellow or amber lenses.
What should you pay attention to when purchasing sunglasses?
1: When purchasing sunglasses, try wearing them to see if you feel dizzy or having a headache. There are also some myopia sunglasses on the market with prescriptions marked on them. However, because indicators such as interpupillary distance vary from person to person, consumers are advised not to choose sunglasses with prescriptions without the guidance of professionals.
2: First observe whether there are scratches, impurities, bubbles, and streaks on the lenses, and check the outer packaging of the sunglasses. Regular sunglasses should be marked with the product name, color, diameter, quality level, manufacturer name and trademark, and there are precautions on the mirror or hangtag. Sunglasses with UVA, UVB and CE marks can ensure a certain level of blocking of external rays.
3: In addition to matching the color of your sunglasses according to your skin color, face shape, and clothing, you should also choose according to the place you enter and exit. Generally speaking, black, brown, and gray have good light filtering effects; gray lenses can absorb any color spectrum evenly, and the scene you see after wearing the glasses will only become darker without obvious chromatic aberration; brown lenses can filter out a large amount of Blue light can improve visual contrast and clarity, and is particularly effective when worn under severe air pollution or foggy conditions.
4: Hold the sunglasses with your hands and face the fluorescent lamp, and let the reflective strips on the mirror roll gently. If you find that the shadow of the fluorescent lamp reflected on the mirror appears wavy or distorted, it proves that the lens is uneven. Such a mirror will damage your eyesight.
5: What color depth of sunglasses is suitable for us? A simple self-test method is to put on the sunglasses in front of the mirror until you can vaguely see your own pupils. If the color is too light, the filtering effect will be too small; if the color is too dark, it will affect vision and weaken the color perception. The colorful light-colored sunglasses that are popular this year should not be used for water activities at the beach, in strongly reflective snow, or under the sun with very strong sunlight. Instead, you should wear sports sunglasses. Most of them use bright saturated colors that can absorb or Reflects more visible light.
6: The lenses should be flat and have high clarity. Sunglasses are made of glass and resin, and the best sunglasses should use polarized lenses. It is made of the same lightweight and precise synthetic resin as contact lenses. It is composed of seven layers of thin sheets. The outer two layers are super-hard wear-resistant layers; the second and sixth layers are shatterproof reinforced layers; the third and fifth layers are ultraviolet rays. Filter layer, the middle layer is the polarizing filter layer. Polarized lenses can effectively filter out reflected light and harmful ultraviolet rays, and are shatterproof and anti-wear. They are the most popular sunglasses.
