Sunglasses are now some of the most popular accessories
However, sunglasses are mainly used for vision protection- this is also why so many people love to wear sunglass wear when summer comes. And there is really no great difference among sunglasses manufactured by any manufacturer or designed by any designers, in terms of functionality.
Though over-exposure to sunlight can really do great damage to eyes- UV rays in sunlight can injure eyes, exposure within certain extent is beneficial for eyes. Therefore, it is not needed to take sunglass wear at anytime when go outdoors. And these protective eye wear are only needed when people go to places, where light are too bright or too powerful. For example some protective glasses are needed when people drive at night or ski in the snow field.
The reason why people should wear protective eye is firmly linked to UV rays in the sunlight. UV rays can be fallen into two types, namely UVA and UVB. Each of them will cause great damage onto different part of eye tissues. In particular, UVB can lead to cataracts and many other serious vision problems.
However, the environment around become worse than ever before, especially UV rays become much prevalent than ever before as more damage is caused to ozone layer. This has also led to a much higher risk of getting cataracts and many other problems.
It is true that eye lens can also block UV rays to some extent, but strong rays can really cause great vision injuries. And the damage of UV rays can also be accumulated as time goes on, and people may get cataract or become blind as a result.