Dogs are "color blind, was thought for a long time. And in fact, they don’t see a certain color spectrum as clearly as we do. Instead, they perceive things that remain hidden from our sense of sight. Have you ever heard the saying: "My dog sleeps in his bed because his basket is haunted"?? There might be some truth to this, so to speak!
In fact, dogs are so-called "dichromats", that have two different types of photoreceptors, i.e. can perceive two color spectra – we humans, on the other hand, have three of these photoreceptor "cones" and therefore see three color spectra. Dogs see colors in the blue-violet and yellow-green range. So you are missing the perception of the red color spectrum – comparable to a red-green-blind person. Many fish and birds, but also other animals, even have four types of cones, so they see more colors than we do!
Dogs see green and red as shades of gray and brown, while they can see things in blue or yellow very well. For example, for a predator, from which our dogs are descended, the ripeness of fruit, which we recognize by its color, is much less important than perceiving the smallest movements. "Blue" Light from our smartphones and monitors – how clearly does it shine for dogs??
Field of vision
Due to the slightly lateral arrangement of the eyes in the skull, dogs have a much larger field of vision than we do, in other words: more all-round vision. Their field of vision is about 240 degrees whitet, that of the human only ca. 180 degrees. Therefore a dog takes quasi "out of the corner of the eye" perceive things that we do not see for a long time. So it may not necessarily have been a sound or a smell that alerted the dog to something we missed. Of course, this is often the case, but not always.
Good vision even in the dark and the perception of movement are crucial for predators, from which the domestic dog descends. Also the domesticated dog used to wake up the whole yard with his barking when approached by strangers or predators or catch rabbits for us. Today we want our family dog to do neither, and find it distressing when he suddenly barks at joggers in the dark that he would ignore in the daylight.
But that is simply because dogs are "relative"short-sighted" are in comparison to humans, and therefore recognize contrasts much more clearly: light/dark for example or moving/unmoving. Almost everyone knows the effect that if you stand very still, the dog no longer recognizes the human from a certain distance. As soon as you start moving, he can see you well again.
Like cats, dogs also have a kind of "residual light amplifier", with which they see better than we do in twilight and darkness. And warn us of strangers that we have not seen at all.
Perhaps the biggest difference, however, is that dogs – like many other animals – in the UV spectrum to see. We humans cannot do that! Things that are only visible to us under a black light lamp, dogs recognize just like that. Luminous objects, which we can only see in the dark when they are "charged" with enough light are always shining for dogs. They detect differences in surfaces and materials that we cannot see because they appear uniform to our eyes.
they also see urine – of mice for example, but also that of conspecifics. If we have wiped away their puddle, they will recognize even the smallest splash that has been overlooked. Lightning is much more visible when the eye can also perceive the ultraviolet light component in it, as well as auroras and other celestial phenomena.
Seeing in the ultraviolet spectrum must have quite curious effects that we can hardly imagine. Maybe the "spook" an outline in an old layer of paint, which the dog still sees under the top layer, but we don’t. when we use a toothpaste with fluorine, the paste glows brightly, even in small traces. How do we look to the dog when we grin with traces of toothpaste around our mouths in fluorescent neon?? Or protect our face (possibly only partially) against the sun with UV-blockers?
Take your dog therefore calmly "seriously, when he seems to see ghosts. Maybe he really does see things that are hidden from you – though not necessarily of a supernatural nature!
Just feed them fresh with proCani! #dogsloveprocani