The structure of the eye and its work

August 12, 2017 17:50 | Yoga For The Eyes

Eye is located in the orbital cavity of the skull.From the orbital bone cavity to the outer surface of the eyeball spherical fit muscles that rotate it.In the future, we specifically focus on the work of these muscles, because, as we shall see, they are directly related to the strength of our vision.

organs surrounding the eye, designed by Nature to protect it from the harmful effects of the environment.Hairs eyebrows withdrawn in hand running down from his forehead with a liquid (usually perspiration), eyelashes prevent dust particles from entering the eye.Lachrymal gland located at the outer corner of the eye, it also belongs to the protective authorities.It allocates a tear, which always wets the surface of the eyeball, does not dry out the living cells of the external layer of the eye, warms it washes away foreign particles fall on the eye, and then drains from the inner corner of the eye for the tear ducts into the nasal cavity.How

arranged eye?Thick albuginea {sclera), covering eyes from the o

utside, protects it from mechanical and chemical damage from the ingress of foreign particles and microbes.In front of the eye, this shell becomes

in a transparent cornea, which, like the glazed window, freely transmit light rays.Average - vascular sheath is permeated by a dense network of blood vessels that supply blood eyeball.On the inner surface of the shell is a thin layer of the colorant - black pigment, that absorbs light rays.In front of the eye, in front of the cornea, the choroid becomes rainbow, which may have a different color - from light blue to black.It is determined by the amount and composition contained in the shell of the pigment.The cornea and iris are not adjacent to each other tightly.Between them is a space filled with a completely clear liquid.

cornea and clear liquid passes the light rays that fall into the eyeball through the pupil - hole located in the middle of the iris.It is necessary to get into the eye the rays of bright light, as there is a reflex contraction of the pupil opening.In dim light the pupil, on the contrary, is expanding.Directly behind the pupil is a transparent lens , shaped lenticular lenses and surrounded ring, or differently, ciliary muscle. According to Western science, the ability to reduce muscle ring

and relaxation, on the one hand, and the natural elasticity of the lens - on the other hand, are the main focus in terms of the eye.For this issue we will return in the future, here in passing, we note that we share this conviction of our Western colleagues only in part.

After passing through the lens, and then through a transparent, like a pure crystal, vitreous, which fills the entire interior of the eyeball, the light rays fall on the inside, very thin membranes of the eyes - retina. retina, despite the fact that it is extremely thin (thickness because it varies from 1/33 cm to less than half of this value) is extremely complicated structure.It consists of eight layers of which are believed to be the only one associated with the perception of visual images.This layer consists of tiny rod-shaped and kolbochkoobraznyh cells differ from each other and form a very unevenly distributed across the retina.These cells are called svetovosprinimayuschie visual receptors. They are under the influence of irritation caused by the rays of light, there is excitement, which is held by spikes neurons, gathering in the optic nerve. As it gets excitement in the brain.

placed in the retina of the visual receptors are divided, as we were told by two different from each other in structure and functions of the group - the so-called rods and cones . Sticks irritated weak dim light, but do not have the ability to perceive color.The cones are stimulated only bright light and are able to perceive color.Emerging in the receptors of excitation passed by centripetal neurons, processes in which a certain portion of the retina are going, as we have said, in the optic nerve.It passes through the shell of the eyeball out of it and goes to the brain.At the point where the optic nerve exits the retina, there are no svetovosprinimayuschih cells.Images of items that arise in this area, is not perceived by us.That's why he got the name blind spot.

In the middle of the retina, directly in front of the pupil, is a small round elevation - the so-called yellow spot , is a collection of cones.Because most clearly we see the objects that are directly in front of the pupil.At the center of this spot is placed fovea - deep pit darker color.In the center of the fovea no one sticks and cones are elongated and closely pressed against each other.Other layers in this place, on the contrary, is extremely thin or even disappear.Outside the center of the fovea the cones become thicker and less frequent, alternating with chopsticks, the number of which is increasing all as you move to the edges of the retina.

macular ability to give the brain a detailed information about the subject under consideration is associated with a very high concentration here svetovosprinimayuschih elements, as well as with the fact that each cone is connected to its own individual neurons.The sticks of the individual neurons do not have and have grouped whole clusters around a single cell.

Cones are not only in the macula, and in other sections of the visual field of the central portion, but their concentration is significantly lower.And on the periphery of the cone is not at all.There are only sticks - svetovosprinimayuschie elements of higher sensitivity.Since a few sticks send their information in the same nerve cell, in the twilight of a very weakly excited sticks joint efforts may bring a neuron and the eye is still something to see, while the cones, which are addressed only to its own nerve cellsin this case, powerless.It was a minor involvement of cones at twilight phenomenon is explained by the fact that the human eye all cats are gray at night.

Thus, by means of sticks we use only at dusk, when the cones are just a nuisance.We could see at night better, if not the habit of focusing an image on the macula - the so-called central fixation.Therefore night we better see objects, the image which appears on the side portions of the retina, and this happens when we do not look directly at the object that we want to see.Incidentally, for the development of this skill is exercise number 3 of group V (§ 20).

Since night vision is completely or partly useless significant portion of the retina - is the one which is so familiar and comfortable to use during the day, then, to see well at night, but you need to train at twilight peripheral areas, ie, those that day bring us littlegood.

Come, however, continue.Receptors eyes perceive visual stimuli due to the fact that there are images on the retina visible contact objects.How does this happen?The rays from the objects, which is directed our opinion, pass through the cornea, the fluid located between it and the iris, lens and vitreous body.In each of these environments, they change direction - are refracted.This process of refraction of light rays in the optical system of the eye called refraction. But the more precise it would be understood by refraction refractive power of the optical system of the eye.

And then we finally came to a rather sensitive issue, in which our views differ from the views of the orthodox Western science.This question is how the process accommodation, ie adaptation of the eye to vision at a distance.However, we must warn the reader in advance that are not going to insult here the best feelings of our Western scientific colleagues or work with them any detailed debate on the affected area.We simply point out what's going on, and concern for clarifying the truth of the whole reserve in charge of our Western friends.

When viewing near objects they clear image on the retina can occur only if the refraction of the eye is larger than when viewing distant objects.And most ophthalmologists believe that the main value for the refraction of light in the eye has a lens.They believe that we can see clearly how the objects that are at a relatively great distance from us, and the objects that are close to us, just because lenticular lens can change its curvature due to the surrounding circular muscle, become more convex orflatter.When circular muscle compresses the lens, it is, in their opinion, should increase its curvature;and as soon as the muscle relaxes, the lens, due to the natural elasticity of the newly flattened.

When viewing objects close to the eye ring muscle strains, and the lens curvature increases, so the refraction of the eye becomes large, and there is a clear image of the retina of the subject.

When we look at distant objects, the muscles relax and the lens flattens, allowing refraction in it becomes smaller.That's why with normal vision on the retina in all cases should capture clear images of objects.

Such in outline view of the orthodox ophthalmology.We stopped in such detail on it because, at least in part, but it is true, and,

to go on, we had to learn the relatively simple point.

However, the reality is much more complicated.I must say that Western science is now there is a fairly influential trend, close to many of his views to the point of view of the Yogis, which adheres to a very different opinion on that score.

This school believes that a decisive factor in the eye refraction are surrounding the eyeball direct and obliques. According to this school, the role of direct and oblique muscles are not limited to only those that, being reduced, they turn the eyeball, allowing us thereby to change the direction of view and to consider certain of the objects around us.

purpose of these muscles is primarily a change in the shape of the eyeball, which is as necessary becomes something extended, then flattened in anteroposterior axis, that allows us to achieve image sharpness of objects on the retina according to the distance at which they are removed from our eyes.

With this understanding, the official opinion of the west ophthalmology, believe if the shape of the eyeball is unchangeable, is untenable.It is this view gave rise to a theory that tries to explain the refraction of congenital anomalies of irregular shape of the eyeball.Thus, this theory is credited to the accommodation only the ring muscles and change their lens curvature.This supposedly inherent elongation of the eyeball must be the cause of myopia , and shortening - respectively hyperopia .However, since the shape of the eyeball as required constantly changing, then this theory is exactly the same as that which gave birth to her opinion, is not worthy of attention.

well known that after the removal of the lens from the eye for cataract often able accommodate the same way as before.The mere fact that this relentlessly crosses the orthodox theory of refraction.Dr. William Bates writes on this subject, he observed many such cases.Patients without

only read diamond type in their glasses for distance from a distance of 33 centimeters or less 26 (most difficult in such cases, read it on very small distances), but one patient was able to do it without any points.At the same time, as pointed out by Dr. Bates, retinoscope in all cases showed that there is a real accommodation and that it is carried out not by some convoluted way, what dogmatic attempt to explain this awkward for them phenomenon, but by precise adjustment of focus to the respective distances.Therefore, it is appropriate to talk about the power of direct and oblique muscles of the eye, on the one hand, and the natural elasticity of the eyeball - the other.

sum up our sketch of the refraction of light rays in the eye, we say that we do not share categorical any of the warring parties in the West, as such a categorization would exclude the correctness of the opposite view.In our opinion, each of these two theories is correct, and should not oppose, but to be considered in unity.However, if the activity of the direct and oblique muscles must be recognized as a determining factor in the refractive power of the eye, the lens and the ring of muscle should be left only a supporting function podkorrektsii.This approach, I think, explain all the contradictions and inconsistencies of Western theories are prone to excessive exclusiveness and rivalry.Do not think that Nature, the greatest and most perfect designer creates in their cars or spare parts will tolerate their presence if they will be established.

In the future we, as necessary, yet time will return to this point, and now again turn to the image, which is obtained on the retina.Since the lens is a lenticular lens, the image of objects appearing on the retina is reduced and reversed in accordance with the laws of physics.The complex process of perception of visual stimuli, which began in the retina, ending in the visual area of ​​the cerebral cortex.It is implemented through the visual analyzer, which holds the ultimate distinction irritations.That is why we distinguish the shape of objects, their color, the size, lighting, location, movement.Images of objects on the retina inverted lens, in the brain once again flipped to match with their actual location.This is due to the influence of various mental reasons, among which the decisive role played by the interaction of excitations coming into the brain from all the senses.

eye, so just svetovosprinimayuschee device like a camera or cameras, "sees" as soon as our brain.It was he who puts the information obtained from millions of light-sensitive cells of our eyes, in the intricate paintings;it is here, in the brain, "images appear" made eyes.It is the fact that he sees not the eyes and hears not the ear and the brain, which is the mediator of our soul, our personal "I" in the rough world of matter, explains the curious fact that we so often see or hear is not what is, but onlywhat we already know or familiar.How many times have each of us caught myself on the fact that it is not noticed any peculiarities in the subject dozens of times before we had seen until someone else who knows, I did not tell us about it!