Summer has arrived, fashionable and practical sunglass near me now have become a necessary item for many people to travel, and the reason for everyone to replace sunglasses is mostly broken, lost, not fashionable enough...

 

You know what? Sunglasses also have an "expiration date" and can cause eye damage if they work past their expiration date.

 

How often should you change your sunglasses? The more expensive the sunglasses, the better the sun protection? Should I buy a dark or light one? ...

 

Let's see, all that stuff about the sunglasses!

 

The sun protection ability of sunglasses is weakened year by year, it is recommended to replace it once every 2 to 3 years

 

The basic material of the sunglasses lens itself can absorb a little ultraviolet light, the coating of the sunglasses lens can also reflect a part of the ultraviolet light, and many sunglasses will also add ultraviolet absorption raw materials in the lens. In this way, most UV rays can be "shut out" and can no longer harm our eyes.

 

But this protection is not permanent.

 

Because ultraviolet light carries high energy, it will age the material of sunglasses and reduce the ability of sunscreen ingredients to absorb ultraviolet light. The shiny coating on the outside of the sunglasses is actually the result of metal vapor deposition, and these coatings may wear, oxidize, and reduce the reflective ability. All of these will reduce the ability of sunglasses to prevent UV rays.

 

Professor liliane ventura of the University of Sao Paulo, Brazil, and her team did a study: in Brazil, wearing sunglasses for two hours a day, after two years, the UV protection of sunglasses will decline and should be replaced.

 

Combined with the sun exposure in China, experts suggest that depending on the frequency of use, sunglasses should be replaced in 2 to 3 years.

 

Sunglasses "extended service" injury or myopia aggravation, cataracts

 

On the one hand, the already worn lenses are extremely prone to dispersion and other phenomena, and wearing such sunglasses is easy to cause visual fatigue, dry eyes, astringent eyes and other conditions, which may also lead to increased myopia.

 

On the other hand, such unqualified sunglasses have been unable to completely block the entry of ultraviolet rays, which will cause a series of negative effects on the eyes. The World Health Organization has published an article "Ultraviolet radiation and Human health", which states that 5% of the 18 million people worldwide who go blind each year due to cataracts are caused by ultraviolet radiation. Ultraviolet light can also cause other serious eye diseases - keratitis, retinal destruction, cataracts, macular disease, snow blindness, etc.