How to choose sunglasses？

When choosing sunglasses, you should pay attention to:

1. Go to a regular eyeglass shop and choose sunglasses with anti-ultraviolet function produced by a regular manufacturer. Glasses sold by street stalls and hawkers often do not meet the UV protection standards, so it is best not to buy them.
2. When choosing, pay attention to the surface of the lens to be smooth, without ripples, defects, bubbles, and wear marks. Lay the lens flat and observe whether the lens is warped from the horizontal direction. Lenses with unevenness, marks or bubbles are not suitable for purchase.
3. The color selection of the lens should be based on the principle that the color of the surrounding environment after wearing it is not distorted, the edge of the object is clear, and the signal lights of different colors can be effectively identified.
4. When buying sunglasses, you have to consider the matching relationship between it and eye size, face shape, eyebrows, and nose.

Judging the quality of sunglasses should be based on:

1. Look at the product label or manual to see if there is an anti-ultraviolet logo.
2. Observe if there are scratches, impurities and bubbles on the lens.
3. Check the lens for optical defects: hold the sunglasses, straighten your arms, and observe the right angles or straight lines (such as door frames, windows) in the distance through the lens. Slowly move the frame up, down, left and right. If you find distortion, skewing, or bending, the lens is not qualified.
4. Check the quality of the frame. Place the sunglasses flat on the counter. If the glasses cannot be placed steadily, there is a problem with the frame.