What are the benefits of gradient tint sunglasses?

[Tomkins Cove]

I just can't understand why people have their sunglasses made in gradient tint. what are the benefits of gradient tint sunglasses?

[Massena]

Gradient tint sunglasses lenses are clear in the button part of lenses and dark in the upper part of lenses. The design of the lenses allow people get clear vision for reading through the lower part of lenses while protect the eyes from UV ray. And the dark upper lenses are block strong sunlight so as to give you comfortable visions. So, wearing gradient tint sunglasses can get more comfortable and convenient vision for life.

[Massie]

gradient tint sunglasses have dark color in the upper part and gradually become to lighter color when come to the bottom part. This kind sunglasses are very convenient to you when you need to read in the bright sun light. The upper part with dark color can protect your eyes from strong light and UV rays and the bottom part with lighter color allow you to read clearly without affecting your vision. For example, you can read a newspaper or a book through the bottom part of the gradient tint sunglasses on a sunny day while the upper part blocks the sun light.