Polarized sunglasses can effectively filter ultraviolet rays, glare, scattered light, refracted light, and other light. When worn, they can effectively reduce eye fatigue and do not feel eye soreness. "Non polarized sunglasses only have the function of filtering ultraviolet rays and resisting strong light, which can withstand less light than polarized ones, and when worn, they do not reduce visual fatigue.".

Sunglasses with dark colors are good because dark colors can effectively block ultraviolet rays in external light, prevent eye exposure to ultraviolet rays, and prevent eye burns caused by ultraviolet rays. Of course, light colored sunglasses are also good, and you can choose to buy them according to your personal preferences.

No matter what color you choose, you should first pay attention to the UV protection label. UV protection is the primary function of sunglasses. Some sunglasses have labels such as "100% UV protection", "UV400", and "UV protection" on their lenses or packaging. If you wear inferior sunglasses that cannot block ultraviolet rays, more ultraviolet rays enter the eyes than if you do not wear sunglasses, which is more likely to cause eye damage. Formal eyewear shops generally have instruments to test the UV resistance of sunglasses.

Some recent studies have found that blue light entering the eye can harm the eye, and blue lenses cannot filter out the blue light in the solar spectrum. Therefore, it is best not to choose blue lenses when choosing sunglasses.