Accommodation - what it is, excites many people. In fact, it is one of the features inherent in the eye, which allows you to distinguish things located at different distances from each other. The whole process occurs automatically and is one of the unconditioned reflexes. To understand the concept of accommodation, what kind of action it is and how it happens, you need to answer a few questions.
Initial stage of the process
The signal to the beginning of this action is the appearance of a fuzzy image of an object, which appears due to the different focusing of the light rays that enter the organ of vision.
In order to cope with this, the body begins a process such as accommodation. What this can be understood by seeing the structure of the muscular system of the eye. Depending on what the person sees, the muscles can both relax for better visualization, and vice versa, strain strongly. Objects that are located close require intense tension from the eye muscles. That is why you can not sit in front of a computer for a long time. This will lead to overstrain, and as a result, myopia or other disturbance of accommodation may develop.
Process essence
This phenomenon has been studied for a long time. Despite the apparent complexity of such an action as accommodation, what it is and what it depends on, the scientist Helmholtz was able to tell in great detail in the middle of the XIX century.
The main role in this process is played by the lens. It can be round, can be extended, and sometimes become completely spherical. Such changes do not occur evenly. The curvature on the front surface changes most strongly, which makes it possible to increase the refractive power.
In addition, modern theory includes information that additional accommodation, which Dr. Anin's studies can describe in more detail, is achieved by changing the length of the eyeball.
Age changes
Violation of accommodation most often occurs as a result of age-related changes in the visual apparatus. With aging, the fibers of the lens become denser, as a result of which it strongly loses elasticity and practically loses the ability to change its curvature. Accordingly, the visual organ cannot adapt to work with objects located nearby. This phenomenon is called presbyopia. It occurs in people who have reached the age of 40 years. Such people have big problems reading. To correct this violation, it is enough to choose the right points.
Paresis
Paresis of accommodation is a pathological condition characterized by the inability to examine small objects due to paresis of the ciliary muscles of the visual organ. By origin there is a central, as well as peripheral, against which the ability to distinguish small objects that are close to a person is reduced. The first form of pathology is often found in infectious diseases, diabetes mellitus, as well as heavy metal poisoning. But the peripheral paresis of accommodation develops as a result of taking medications belonging to the group of M-anticholinergics.
Spasm of accommodation
This term is called a condition in which the ciliary muscle is disrupted. As a result, the visual organ loses the ability to clearly see objects located not only near, but also in the distance. One of the main reasons that can lead to this pathological condition is fatigue. The main manifestation is the appearance of severe pain and pain in the eyes during prolonged sitting at a computer or reading. The patient has redness, often lacrimation can be seen. The patient complains of severe headaches, increased fatigue and decreased performance. As a treatment, you need to choose the right glasses, as well as carry out such a simple procedure as training for accommodation of the eyes.
For the purpose of diagnosis, it is necessary to conduct a set of studies: determining the volume of accommodation, visometry, studying the refractive ability of the eye. The first of them, that is, the definition of accommodation, is called "accommodation".
Paralysis
This concept refers to the type of vision impairment in which objects are not visible at close range. This is due to a violation of the nerve impulse. The reasons for the development of this pathology are many. This can be either an infectious disease or a mechanical injury.
In addition, this visual impairment can cause an overdose of drugs. An example is atropine, which is often used by ophthalmologists in medical practice. Due to the fact that the ciliary muscles responsible for accommodation have one innervation with the sphincter of the pupil, this disease will always be accompanied by mydriasis - the maximum possible expansion of the pupil.
Due to the fact that the near point of clear vision almost merges with the distant one, the patient's vision is impaired. To correct it, it is advisable to use special glasses designed to work close. In the event that the paralysis is traumatic in nature, it cannot be treated and corrected, and it remains to wait for the moment when it passes on its own.
Training number 1
One of the most popular exercises, which allows you to restore the former ability of the eye to see and normalize the mechanism of accommodation, is the so-called mark on the glass. It can be performed with one or both eyes. When performed with two eyes, the distance to the mark should be approximately 30 cm, and the object behind the glass should be located at the farthest distance. Moreover, it should be at least 5 meters.
We look at the mark for about a second, after which we translate the look at the subject. Then the exercise is repeated with each eye separately, moreover, the opposite should remain closed. You need to load the one that sees worse.
The main convenience of this exercise is the ability to perform it even on the street. Here, the closest object is not a point on the glass, but the tip of the nose. Any item you see can be selected as a distant item. Unlike other exercises aimed at restoring normal visual ability, accommodation training has no time limits.
Training number 2
The second exercise, which is suitable for improving the accommodative abilities of the eye, is carried out using reading glasses. In this case, the accommodation zone is very small, and the distant point of view is no further than 40 cm. Exercise should be performed with one eye. This is necessary in order to eliminate possible convergence.
The exercise itself consists in the fact that the patient takes the text and moves it to the eyes until the letters are blurry. Then the text moves away from the eyes until the letters also begin to blur. This exercise is advisable to combine with reading. It should be remembered that it can not be performed too often, as this can lead to eye damage and visual impairment.
Another exercise is the complex between the first and second. To do this, you need to stand at the window and mentally draw a horizon on it. Then a small text is taken into the hand and slowly approaches the open eye. After all the letters are blurry, the text begins to slowly move away, trying to consider it as best as possible. The cycle is repeated several times, then through the window you need to try to consider far-lying objects.
Accommodation training is an extremely important process that helps many patients to recover. That is why this procedure cannot be neglected, and it should be performed often enough. The only thing worth remembering is to consult with a specialist who will not only find the reason for the deterioration of the accommodative ability of the eye, but also select the most appropriate solution.