1. Has UV protection logo
UV protection is the primary function of sunglasses. Some sunglasses have “100% UV protection”, “UV400”, and “UV protection” logos on their lenses or packaging. If you wear inferior sunglasses that cannot block UV rays, more UV rays enter your eyes than when you don’t wear sunglasses, which will more easily cause eye damage. 
After a long period of time, it can cause cataracts, and symptoms such as eye pain, corneal edema, and corneal epithelial peeling will occur. . Regular spectacle shops generally have instruments to test the ability of sunglasses to prevent ultraviolet rays, which can detect whether your choice is correct. However, the quality of spectacle lenses from street stalls and hawkers is often not up to standard, so it is best not to buy them.
2. Choose gray, brown and green lenses
The color of the lens should be based on the principle that the color of the surrounding environment is not distorted, the edge of the object is clear, and the signal lights of different colors can be effectively identified. The colors of the lenses are gray, brown, and green because the lenses of these colors absorb infrared and ultraviolet rays better.
3. Medium depth lenses
Generally speaking, the darker the color of the lens, the stronger the shading effect, but it does not mean that the ability to prevent ultraviolet rays is stronger. The anti-ultraviolet function of sunglasses is also related to factors such as the material and technology of the lens. The lenses are generally medium-depth. Of course, if a strong shading effect is required, darker lenses should be selected. But cyclists or motorists should not choose too dark lenses, otherwise it will be difficult to recognize the color of traffic lights.
4. The occasion determines the angle of choice
When going out for activities, you should choose different sunglasses for different occasions. For example, some sports sunglasses, their frames are specially made to protect the eyes according to different needs, and can be worn comfortably and firmly, such as water skiing, skiing, mountain climbing, golf, and tennis. Sunglasses. For those who love golf and tennis, amber lenses can effectively increase the contrast and absorb blue light, which contributes to visual comfort during sports.
It is best to wear swimming goggles with anti-UV treatment when swimming outdoors. It is best for drivers and fishing enthusiasts to choose polarized sunglasses, because polarized lenses can eliminate glare from all directions and make objects look clearer.
Precautions for choosing sunglasses
1. Don’t choose sunglasses that are not UV resistant
It’s fun to buy a pair of sunglasses at a roadside shop? Those inferior sunglasses that are not UV-resistant are not as good as not wearing them.
Wearing sunglasses is to prevent light and ultraviolet rays from harming the eyes. Firstly, shading can prevent headaches caused by glare; secondly, if the ultraviolet rays in the sun enter the retina, it will cause macular degeneration and even cataracts and other eye diseases. Inferior sunglasses only use colored lenses to block the light. Human pupils will naturally dilate in low light. However, inferior sunglasses lenses do not have the function of preventing ultraviolet rays. The enlarged pupils will absorb more ultraviolet rays, which is easy to cause cataracts. Solar keratitis, corneal endothelial damage and macular degeneration of the eye and other diseases.
2. The lens of the sunglasses should be smooth and free of wear marks
When choosing the lens, pay attention to the surface of the lens. It should be smooth and free of wear marks and bubbles. Place the lens flat and look at the lens from a horizontal direction without warping. You can take the sunglasses 45 cm away from your eyes, observe the vertical and horizontal lines around you through the glasses, such as window frames or door frames, and then move the glasses up and down. If the straight line is distorted or oscillated, it means that the lens is deformed and should not be purchased. Lenses that are uneven or have marks or bubbles will cause discomfort such as dizziness after wearing them, so they are not suitable for purchase.
3. Pay attention to prevent sunglasses syndrome
Sunglasses syndrome refers to long-term wear of sunglasses, resulting in decreased vision and blurred vision. In severe cases, symptoms such as headache, dizziness, vertigo, and inability to see for a long time can occur. This symptom is manifested in a variety of discomforts, such as obvious numbness and tingling in the eyes near the nose in the early stage, and the symptoms are more obvious when breathing, much like a cold, and some people feel like a small bug crawling on the face. Walking, the upper jaw gums are numb, the upper incisors feel uncomfortable, and the local blood circulation is not smooth, causing skin inflammation, eye swelling, and vision loss. These discomforts usually appear after 2-3 weeks of wearing sunglasses.
To prevent sunglasses syndrome, first of all, we must choose and use sunglasses properly. Choose glasses with the same distance between the pupils and the shape of your face. In addition, do not wear large sunglasses as much as possible. When you must wear them, you must shorten the time to wear the glasses. After removing the glasses, use your fingers to massage the eye sockets and both sides of the nose 10-20 times. Once sunglasses syndrome occurs, you should stop wearing sunglasses immediately.
Therefore, sunglasses are not the more expensive the better. It is the right way to block ultraviolet rays.
Post time: Nov-11-2021