The eye, the construction (anatomy) the eyes

The light was an irritant that has brought to the creation of the Flora of the special organ of vision, organum visus, much often in all animals the specific sensitive cages that have happened in and being able to perceive the stimuli of the light beams. They are of the pigment mostly surrounded whose meaning is to miss the light in a certain direction and to absorb the unnecessary rays of light.


Such cages at the lowest animals according to the body (the primitive "spies") apart thrown and below the recess is formed. From sensitive cages (the retina), to which the nerve is zoom In front of the recess, the invertebrate Wednesdays arise (the eye lens) for the concentration of the light rays which fall on the retina. In vertebrates, which can reach the eyes of the most development, appear, in addition, the muscles that move the eye, and the safety devices.

A characteristic of vertebrates that fact that the light-sensitive covering of the eye (retina), containing the specific cages, not straight, and the distance from the anterior brain bubble is developed.

In the first stage of the development of Sehanalysators (the fish) at the peripheral end (the retina) are the light-sensitive rods of the cage, and in the brain, there are only the visual centers, which are the average brain. Such an organ of vision is only to distinguish the objects and the gifted. Among the land animals, the retina is the light-sensitive new cages - complements and there are new visual centers in the brain, intermediate, and mammals -. And bark Thanks to him, the ability to get the eye color vision. All that is connected to said first signal system. Finally, in humans, the peculiar development the highest centers of sight reach the cortex of the brain, thanks to which arise in him, abstract thinking, which is connected to the visual images and the written speech, which a part of the second signal system, the only proper to man, the eyes are done in the following way in general. Side the walls of the front brain bubble (its part, the intermediate brain) is, extending to the sides form two eye-пузырька, reported by becoming the hollow shaft with the constricted brain cavity. Out of the handle is formed неpв, and from the peripheral part of eyes - the retina. In connection with the development of the eye lens of the front part in the direction of eyes-пузырька after stem, whose result is the "eyes wineglass" transformed.

Both sheet go over the edge "of the wine glass" a образуя in others, the seed of the pupil. Outwardly, the sheet "of the wine glass" a pigment layer of the retina, and intra - sensitive to light (actually the retina). In the front part "of the wine glass eye" forms the eye's lens, which is housed in the caves, and behind the eye lens - the body.