Summer Is Coming, How To Choose Sunglasses?
Uv rays are the most damaging of sunlight and have been linked to eye diseases such as cataracts and retinopathy. Ultraviolet rays make up about 7 percent of the sun's light that reaches the earth's surface, so we often wear sunglasses to protect our eyes from ultraviolet rays when we're outdoors, especially when we're playing sports or driving. Summer is coming, how to choose the right sunglasses?
Ultraviolet light, discovered in 1801, is an electromagnetic wave. Ultraviolet (UV), which we know a lot about, is ultraviolet light. As its name suggests, it is "light beyond purple", not purple, because it has a shorter wavelength than violet, which is beyond the range of the eye and invisible to the naked eye.
The main ultraviolet light source in nature is the sun.
Artificial ultraviolet light source is widely used in our daily life, especially in the medical field, is very common, in addition to the sterilization, disinfection, and to treat skin disease rickets, etc., the right amount of ultraviolet ray can regulate sleep, relax mood, relax the pressure, human skin may use ultraviolet light to synthesize vitamin D, vitamin supplements, also promote the body to the absorption of calcium.
However, excessive UV rays can cause harm to the human body, most commonly to the eyes and skin.
Types of sunglasses
The sunglasses we're talking about today are glasses that protect against ultraviolet rays. The lenses of this kind of glasses have been added in the production process of anti-ultraviolet material, can effectively prevent it from entering the eye, even colorless and transparent lenses can also resist ultraviolet damage.
Currently, the relevant standards in China divide sunglasses into three categories: sunshade, light-colored sunglasses and special-purpose sunglasses.
Sunshade mirror is a commonly used sunglass, which has a more obvious blocking effect on the sun and can reduce the harm caused by strong light stimulation on the eyes.
Light-colored sunglasses are suitable for cyclists or motorists, or indoors where the sun is not strong. Because cyclists or motorists travel faster than pedestrians, a low transmission ratio can affect their reflexes.
Special purpose sunglasses are used in outdoor areas where the sun is strong, such as beaches, skiing, and mountain climbing.
Colored glasses are sunglasses
The pupil of the eye shrinks or dilates depending on the light. When we wear colored glasses, the light entering our eyes is dimmed, and our pupils dilate accordingly. Once we wear glasses with no uv protection function, the dilated pupils will "receive" more UV rays, causing more damage to our eyes.
As long as can prevent ultraviolet ray is qualified sunglasses
Most sunglasses are in the flat lens series. This kind of sunglasses, according to the relevant national professional standards, is only allowed with a maximum of plus or minus 8 degrees of refraction, if the error range exceeds this, the wearer will often appear dizziness, nausea, dazzling and other symptoms. In addition, some sunglasses can have both myopia correction and other functions, we must pay attention to the quality of the product when choosing.
Buy children's sunglasses at will
Children's eyes are still in the growth stage, more attention should be paid to protection. Parents do not want to convenient and buy at will, of course, used to do toys, props except.
Polarized lenses are a good choice
As we all know, sunlight is to illuminate in all directions, when shooting to the object, the light is redirected and reflected, forming horizontal, vertical two kinds of reflected light, the former is the disorderly reflected light that causes dazzled, this is the polarizing light that affects the line of sight. The main function of polarizing lens is to filter reflected light effectively. It has a special filter material to filter out the reflected light caused by water, wet or sunny roads and wet sand. After testing, qualified polarizing lens can filter out 99% dazzling disorderly reflected light, 96% ultraviolet ray. Normal sunglasses cannot overcome the reflection of polarized light, in this kind of polarized light filter lens, that is filtered, the remaining vertical light into the eye, feel comfortable and clear.
Don't wear sunglasses for a long time. Some people wear sunglasses all day and even at night when they go indoors to look cool. In low light, the contrast of objects is reduced, and the eye has to "work harder" and "hurt more" to see better.
