What do you call glasses that change color ?

[Weslaco]

I heard that this is a types of wonderful glasses. The glasses can change color of their lenses in the sun. Also it can turn back to transparent lenses indoor. What are the glasses? How do you call them?

[Wesley Hills]

Yes, what you refer to is photochromic lens, or you can also call it transitional lens. It can be easy found in Alibaba.com. This sort of glasses has a special characteristic that it appears dark when specific types of light enters, generally the ultraviolet (UV) radiation. Once you walk into indoors or put the glasses into box removing the light source, the lenses will gradually return to their clear state. It is amazing, isn't? Have a good day.

[Wesleyville]

They are called the transition glasses which could be changed in color. When you are out, the lenses will be changed in the dark color. When you are in the room, your lenses will be transparent. This kind of glasses will protect your eyes from the uv rays in the strong sun light. It could also make you see clearly with prescription when you are short sighted. It is really the good pair of glasses.

[Wessington]

It's called Photochromic lens or transitional lens. It is transparent indoor. But when it is in the sun, the color changes according to the intensity of the ultra violet. The color of the glasses get dark when they are exposed to ultraviolet radiation. It becomes a pair of sunglasses when you are outdoor.While, as long as the light source is taken away,say, entering indoors, the glasses turns back to normal transparency. Transitional lenses can be made of polycarbonate, glass,or another plastic. The advantage and disadvantage of Photochromic lens: Advantage: If you have both vision problem which requires you to wear a pair of glasses and you are also in need of a pair of sunglasses to protect yourself from ultraviolet, you can have photochromis lens as it has both functions of sunglasses and normal glasses. Disadvantage: The color doesn't change quick enough.