What are the reading glasses shade up when you go outside?

[Terrance]

what's it called when your reading glasses change color when you go outside? and how much do they cost?

[Ahmad]

I think they're called transition glasses and only work under UV radiation. These dynamic eyeglass lenses are designed to be worn indoors and automatically adapt when you are in outdoors to give you a more comfortable viewing experience while providing eye protection from damaging UV light. The price difference between them and the regular reading glasses can vary from $10-$100 depending on the brands and material .

[Jamarion]

They re called transition lens.They will change to the tinted color when you're out, and get clear when you come inside.About the price,you can get them quite cheap for $50.