Photochromic lens

Photochromic lenses are glasses that change color when they are exposed to light. This means that when you wear them inside or in the shade, they will look like normal glasses with no tint. But when you step outside into the sunlight, they will darken and become sunglasses.

It's kind of like how a chameleon changes colors to blend in with its environment. Photochromic lenses use special chemicals that are sensitive to ultraviolet (UV) radiation from the sun. When the UV radiation hits the lenses, the chemicals react and cause the lenses to darken. The darker the lenses, the more protection they provide against the sun's harmful UV rays.

The great thing about photochromic lenses is that they are not just for prescription glasses, but also for sunglasses. So, if you wear prescription glasses, you can get photochromic lenses that will darken outside and become clear inside. And if you already have sunglasses, you can get photochromic lenses to replace the regular lenses so that they can change color based on the light conditions.

Photochromic lenses are really helpful for people who spend a lot of time outdoors and want the convenience of not having to switch between regular and sunglasses. They are also good for people who may forget to bring their sunglasses with them or have multiple pairs of glasses. So, if you ever need glasses that can change color, just ask for photochromic lenses!