Sunglasses can be divided into three kinds according to their use. The first kind is based on their basic use and function, which are used to hide the strong lights. When we stand in the light, we should adjust the size of our pupils to accustom ourselves to the light. Once the light is too strong and beyond our ability to adjust, our eyes will be hurt. As a result, when we do outdoors sports or labor, especially in summer, we need this kind of sunglasses to avoid our eyes being hurt by the strong lights. Because of their use, this kind of the sunglass is deep-colored.

The second are the light color sunglasses. This kind of sunglasses will not hide the strong lights as well as the first kind. However they have their special advantages. They have a great number of styles. And at the same time, the same style has many different colors. So they can suit our clothes and faces more easily. And we have more choices. This kind of sunglasses has attracted many people’s attention and appeals to the young people. They seem to be more fashionable. So we can buy them easily for they are sold everywhere. They have large market.

The last one is the sunglass that is invented for the special purposes. For instance, the climber, the ski bobbers as well as the people who go to the sea for their holidays need this kind of sunglasses. They can help them decrease the hurt caused by the ultraviolet rays. The common sunglasses do not have this good effect, so these people need to buy this kind of the sunglasses. This kind of the sunglass will cost more money. And they are sold in a few shops. In spite of these, these sunglasses are worth buying and wearing. They are of high quality.

The three kinds of the sunglasses have their own advantages and disadvantages. So when we choose prescription sunglasses, we should know the basic knowledge of them, which can help us choose the best one and the most suitable one.