What actually the dog sees as she perceives the world around? There is a large amount of differences in the structure of the visual device of a dog and the person, and, therefore, and in perception too.
Structure of an eye of a dogThe organ of vision of a dog includes an eyeball and the subsidiary bodies. The eyeball is reported with a brain an optic nerve.
The eyeball consists of a retina, fibrous and vascular covers. The fibrous (external) cover includes to a skler and a cornea. Sclero is the place of fastening of tendons of eye muscles. The cornea answers for carrying out light a retina.
In a vascular (average) cover the pupil, a ciliary body and directly vascular cover at the expense of which there is retina food are located. In a retina photoreceptor nervous cages - the sticks and flasks which are carrying out according to sacred and color sensation are located. For accommodation - the ability of an eye to change focal length - is responsible the crystalline lens located in an eyeball cavity.
Work of an eyeLight gets through a pupil and is focused on a retina by means of a cornea and a crystalline lens. The amount of light coming to an eye is regulated by an iris of the eye due to change of the size of a pupil. The retina perceives light and on the visual channel transfers information to a brain of an animal in the form of a nervous impulse. Plaintive glands protect a cornea from drying. The third eyelid cleans an eye from pollution.
Features of sight of dogsOn the basis of features of the structure of organs of vision and work of an eye of dogs it is possible to mark out the following features of visual perception. Dogs have color sight. In a retina of an eye 2 views of flasks are arranged. These are the receptors which are responsible for flavovirent and dark blue-light blue colors. It means that many color shades various for the person, the dog sees similarly.
Dogs have no receptors perceiving red color, the similar color perception meets at the people having daltonism.
The visual acuity at dogs is much lower, than at the person. Rates of sight are about + 0.5 dioptries. Organs of vision of dogs are capable to distinguish more than 35 shades of gray color, at the expense of bigger quantity of the sticks having high photosensitivity in the conditions of weak lighting. Dogs are capable to perceive a moving object from distance to 900 meters, motionless — only from 600 meters. Width of peripheral sight of a dog depends on features of breed and is about 250 degrees.
If to present a situation that the dog checks sight at the oculist on the table Sivtsev, the healthy animal would distinguish only the third line while the person — the tenth.
The analysis of the structure of visual bodies of a dog and features of visual perception shows that dogs perceive the world around differently, than the person. Though an eye of a dog also concedes to opportunities of human sight in ability to distinguish a rich palette of color, dogs react to moving objects better, are guided in night-time and have broader peripheral sight.