Transitions lenses contain special patented photochromic dyes that cause the lens to activate, or darken, when exposed to ultraviolet rays from sunlight. When the UV light diminishes, the lenses fade back. As light conditions change, the level of tint adjusts, offering the right tint at the right time.
Most frogs and toads breathe (and take in moisture) through their skin through a process called cutaneous gas exchange, but they also have lungs with which they breathe. During the time they stay submerged under water or buried in soil (such as during hibernation) they ONLY breathe through their skin.