Your pet is seeing things. Specifically, your pet is seeing things you can't see, according to a new study from City University London. Researchers found that cats and dogs might be able to see in ultraviolet, allowing them to see a broader spectrum of light than humans can. The discovery could shed light on animal behavior that might seem crazy to us -- like chasing light beams on the wall or pawing at things that, to us, do not appear to be there -- but make perfect sense to animals who quite literally view the world differently.
Using specimens from animals that had already died, researchers measured how much light was able to get through the lenses and to the retinas of an array of mammals' eyes -- from hedgehogs to monkeys. The scientists discovered that many of the animals had lenses that would allow ultraviolet light to pass through. While they haven't confirmed how useful UV-vision could be for the animals whose eyes contained the lenses for it, ultraviolet light is known to serve important purposes for a number of species. Bees, rodents and reindeer, for example, all rely on UV light for survival in different ways: bees pick out flowers for pollination by seeing ultraviolet patterns on their petals, while rodents and reindeer can use the light to see predators that, to the human eye, blend into the landscape.