Inferior sunglasses are unclear and can't resist ultraviolet rays. As a result, the pupils are enlarged, so that the lens of the eyes absorbs more ultraviolet rays, so it is necessary to choose a reputable store to buy. So what should I pay attention to when buying sunglasses?
First, first observe whether the lens has scratches, impurities, bubbles, streaks, and check the outer packaging of the sunglasses. Regular sunglasses should be marked with the name, color, diameter, quality level, manufacturer name and trademark, and the mirror or tag is marked. Sunglasses with UVA, UVB and CE markings are guaranteed to block certain UV rays.
Second, you should wear a pair of sunglasses to try to have a feeling of dizziness and headache. There are also some myopia sunglasses on the market that are sold, but because the distance and other indicators vary from person to person, consumers should not choose this kind of sunglasses without the guidance of professionals.
Third, hold the two corners of the sunglasses against the fluorescent lamp, and let the reflective strip of the mirror gently roll. If the specular reflection of the fluorescent lamp appears wavy and twisted, it proves that the lens is not flat, and such a mirror will damage the vision.
Fourth, the lens should be flat and the transparency should be high. The sunglasses should be made of glass and resin, and the best sunglasses should be polarized. It is made of the same lightweight and precise synthetic resin as contact lenses. It is made up of seven layers of sheets. The outermost two layers are super-hard wear-resistant layers; the second and sixth layers are shatterproof layers; the third and fifth layers are UV rays. The filter layer, the middle layer is the polarizing filter layer. Polarized lenses are the most popular sunglasses because they can effectively filter out reflected light and harmful ultraviolet rays, and have the functions of shatterproof and anti-wear.
Fifth, the color of sunglasses should be selected according to the skin color, face shape and wear. Generally speaking, the black, brown, and gray filters have good filtering effects; the gray lenses absorb evenly in any chromatogram, and the scenes seen after wearing the mirror will only darken without significant color difference; the brown lenses can filter out a large amount of color. Blu-ray can improve visual contrast and sharpness, especially when exposed to heavy air or fog.
Sixth, how is the color shade of sunglasses suitable for us? The simple self-test method is to wear sunglasses on the mirror, to the limit of seeing your own glutinous rice. 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. This year's popular colorful light-colored sunglasses should not be used in the water activities on the beach, in the strong snow, and in the sun with strong sunshine. Instead, wear sporty sunglasses, most of which are saturated with saturated colors, which can be absorbed or Reflect more visible light.
Seventh, wearing sunglasses in addition to reducing glare stimulation, so that the eyes are comfortable, the main purpose is to prevent ultraviolet rays from causing damage to the eyes, and the color of the lens and whether it is UV protection are two different things, even if the lens is dark, it may not be effective to prevent UV, So be sure to choose a lens with UV protection. Usually the UV index of sunglasses is between 96% and 98%.
Eighth, the general regular optical shop will have an instrument to detect the ability of sunglasses to resist ultraviolet light. Through this test, you can know whether the glasses in your hand are helpful to your eye health.