Photochromic lenses are special types of eyeglass lenses that automatically adjust their tint based on the amount of sunlight exposure. When exposed to UV rays from the sun, these lenses darken to reduce glare and protect the eyes. Once indoors or in low-light conditions, they gradually return to their clear state. These lenses are popular among people who frequently move between indoor and outdoor environments, as they provide convenience and comfort. Photochromic technology is commonly used in prescription glasses and sunglasses, making them versatile for various activities while ensuring optimal vision protection.