Cats See Things Invisible To You
Cats are considered by many as symbols of mysticism because of their elegant and flexible body, as well as their gaze that can “magnetize” anyone.b They have this magical presence. And, recent scientific data shows, there is another reason why cats have a title of ‘mysterious’ creatures. That's because cats can see things ... that we can't see with our eyes.
Cats, like some other animals, have the ability to see psychedelic stripes on flowers or fancy patterns on the wings of birds, which are invisible to human sight. The secret behind the super vision of our four-legged friends is the UV light. According to a recent study, cats, as well as dogs, and other animals, can perceive this type of light which humans cannot perceive.
"There are plenty of things that reflect UV radiation, which some sensitive animals are able to see, while we are not” said Ronald Douglas, professor of biology of the City University of London and co-author of the study. “For example, these may be certain patterns on flowers that show where the nectar is, or traces of urine of an animal. Also, reindeer can and see polar bears as the snow reflects UV radiation, while white fur does not."
Therefore, cats, dogs and reindeer can detect with their eyes animals with white fur, while most people will only see… white snow. Douglas, who specializes in optics, and Glen Jeffery, professor of neuroscience of the University College London, indicate to us that cats, dogs, hedgehogs, rodents, bats, weasels and the okapis can detect significant levels of ultraviolet radiation.
“For decades, we have known that many invertebrates such as bees see ultraviolet light,” continued Douglas, saying that even birds, fish and some reptiles were recently added to the same list.
However, scientists believe that most mammals cannot see ultraviolet light because they have no visual pigment with maximum sensitivity to ultraviolet light, but instead have lenses like those of humans, preventing ultraviolet light from penetrating into the retina.
The visual pigments are those that absorb light and turn it into electrical activity, which, in turn, is transmitted through nerve cells. It seems it is not always necessary for sensitivity to ultraviolet radiation. Instead, transparent parts of the eye such as the cornea and the crystalline lens in some animals transmit wavelengths of ultraviolet light. This ability allows more light to pass to the retina, something that would be very useful for a nocturnal cat.
It could also explain why cats show so much interest to ordinary objects, such as a piece of paper. Sometimes chemical substances are added to paper, textiles, laundry detergents, shampoos and cosmetics in order to make objects look brighter. Once these optical brighteners absorb the ultraviolet light, they may look differently in the eyes of animals that are sensitive to UV rays, than they appear to us. Some people, for example, those who have undergone cataract surgery, also can see some of the UV light, but most cannot.
“We all know that ultraviolet radiation can be harmful,” said Jeffery in Discovery News. “I work a lot in the Arctic, where the UV radiation levels are too high as there is much snow and ice. The surfaces reflect 90% of UV radiation, with the result that animals are exposed to it. If you do not wear goggles, your eyes will hurt within the first 15 minutes.”
However, studies on reindeer have shown that repeated exposure to ultraviolet light does not bother them at all. It is possible that cats, deer and some other animals that can detect UV rays have a protective mechanism. Also, scientists believe that UV light tends to create more blur.
“Humans are good at one thing: they can see more details,” added Douglas and concluded: “Maybe that’s why we have a lens that ‘blocks’ ultraviolet light. If you do not have it, the world might appear more blurred.” So the next time your cat stops and stares at something you can't see ... it is further proof that just because we can't see it ... it doesn't mean it isn't there.
Just a thought ...
~Justin Taylor, ORDM., OCP., DM.
My thanks to Anna LeMind, Learning-mind.com.
