Brain controls the motion of eyes

The eyes are not fixed. They are constantly in motion, object tracking, looking from side to side. Our eyes and in the eyes of other mammals, move together. Both are always directed toward what we want to see. Control of eye movements depends on the delicate nerve impulses from a specialized center in the brain. These messages cause the contraction of a set of six muscles that extend between the eyeball and the bone wall that surrounds it. Is the contraction of one or more of the muscles that move the eyes.
wach videosThe outer wall of the eyeball is comprised of three layers "of the fibrous layer and the retinal pigment layer. Fibrous layer is the outer protective layer of the eyeball. Is thick and durable. Much of this layer is turbid or opaque. ( An object is opaque so you can not see through it.) But in the center of the exposed part of the eye, the fibrous layer becomes transparent and is called the path cornea., the cornea is actually a small window otherwise one opaque layer. the remainder of the exposed portion of the fibrous layer is loosely referred to as the white of the eye.
The cornea and the white of the eye is constantly wet from the washing liquid and lacrimal glands. These glands under the blankets in the outer corners of the eyes, wash the main function. Other animals do not cry. One man uses the lacrimal glands, for love and for eyewash. The pigment layer in the fibrous layer. All the cells are filled with tiny grains of pigment color, hence its name. This corresponds to the surface layer of dark black, bedroom, and whose function is to avoid thinking of it. The pigmented layer, of course, does not extend completely around the eyeball. It extends under the cornea. If I did, I could not let the light in his eyes.
The retina is the innermost of the three layers of the eyeball. The sensitive layer is one which reacts when the light enters the eye. Thus, it can be compared with the film in which a shot with a camera. The retina is a cup-shaped structure located in the rear half of the eyeball. The highly sensitive layer consists of a large number of nerve cells. Some of these cells are connected to the brain by means of long strands of cytoplasm which extend outwardly from their cell bodies. These are long strands of nerve fibers. The fibers of the retina of each eye were collected in the bottom of the eyeball. Then pass into the brain monocable, the optic nerve wide.
When light enters the eye first passes through the transparent cornea. This small circle of transparent fabric is directly in front of the student. As you can see by looking at your own eyes in a mirror, the pupil is a small hole in the center of a ring of colorful fabric. The colored ring of tissue is the iris. When we say that a person has blue eyes or brown eyes, we mean that his irises are blue or brown. Iris was the name of the goddess of the rainbow Greeks, and this is the origin of the word.