Photochromic lenses are special eyeglass lenses that automatically adjust their tint based on the amount of sunlight they are exposed to. When outdoors, these lenses darken to reduce glare and protect the eyes from harmful UV rays. When indoors or in low light, they return to a clear state, providing comfort and clarity. These lenses are made with photochromic molecules that react to UV light. They are popular among people who need prescription glasses and want the convenience of not switching between regular glasses and sunglasses. This technology enhances visual comfort and protects eye health in varying lighting conditions.