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The human eye can perceive the space around the point where attention is focused. This process is called peripheral vision. This is a kind of vision function that helps to navigate in the surrounding space.
Human evolution has led to the fact that we are able to capture everything that surrounds us. This is due to both eyes.
There are many reasons that lead to visual fields being disturbed and narrowed. Also, some segments and fragments may not be perceived.
Why is peripheral and central vision impaired?
This may occur as a result of the fact that the eyes are prone to any diseases. It is possible that peripheral and central vision may be impaired as a result of the fact that a pathological process occurs in the human body that affects the central nervous system, which, in turn, involves pathways or higher visual centers in the process. Therefore, if they are diagnosed in time, then serious ophthalmic and neurological pathological processes can be prevented.
If you periodically monitor the fields, you can evaluate the clinical course and prognosis of pathological conditions. You can also track the results of the treatment.
During computer peripherals, it is possible to set boundaries for each eye separately, as well as to determine visual function disorders within it.
Types of computer peripherals
In medical practice, there are 4 main research methods. Let’s look at each separately.
Kinetic study
A specialist can determine not only eye dysfunction, but also any pathological processes occurring in the brain. The study is that the patient must follow the object that moves. In this case, lighting should be minimal. At this time, using a special apparatus, the specialist fixes eye reactions at the moment when the object disappears.
Statistical study
In this case, the doctor may notice many disorders that prevent the eyes from fully functioning. It is also possible to diagnose the development of glaucoma (an eye disease against the background of increased intraocular pressure) in time. The study lies in the fact that the patient must carefully monitor the subject, which is moving all the time. At this time, the illumination is constantly changing, and the apparatus must determine under what light the eye fixes the object better.
Amsler test
The purpose of this technique is to diagnose pathological processes that interfere with the full functioning of the retina. Also, the specialist can determine the state of the central part of the field of view. The patient is given a drawing, and he must concentrate his attention in the center (the drawing shows a black lattice). A person who does not have retinal problems sees a clear image in which all the lines are parallel, the squares are the same, and the angles are right. Otherwise, the image is distorted.
Campimetry
This technique helps specialists evaluate the functions of visual perception. The patient is given a drawing that shows a black square with a white dot in the center. If you focus your attention on this point, then it will begin to move with a certain trajectory. At this time, the device must fix the areas where the point disappears and returns again.
In what cases is it necessary to carry out computer perimetry, and in which it is contraindicated?
Doctors prescribe this procedure if there is a suspicion that the patient:
- intraocular pressure, because of this, serious vision problems may develop;
- pathological processes occurring in the shell of the retina and optic nerves;
- impaired cerebral circulation;
- malignant brain tumor;
- inflammatory processes affecting the central nervous system.
Absolute contraindications are disorders of the mental system. It is pointless to carry out computer perimetry if the patient is under the influence of alcohol or drugs.
How is computerized perimetry performed?
We have already described above the types of computer perimetry and the features of their implementation. They are prescribed depending on the indications of the patient. But there is a standard procedure that is carried out as planned for the timely diagnosis of possible pathological processes or in order to track the dynamics of the therapy.
The patient is seated on a chair, and a special apparatus is placed in front of him, on which there is a light mark. You need to focus your attention on it. It lasts 5-7 seconds. Then other light beacons with different color intensity appear on the screen. When the patient manages to focus his attention on the initial mark and not be distracted by others, he must press the appropriate button.
After that, the procedure is repeated again, only in a slightly different way. Now additional light beacons do not just stand still, but randomly and at different speeds move across the screen. The patient must also press the button after focusing their attention on the main point.
The entire procedure takes approximately 20 minutes. According to the results obtained, the computer makes its calculations, and according to them, the doctor already draws up a schedule that allows you to evaluate the performance of the optic nerves and diagnose a possible pathological process.
How does the specialist interpret the results?
All the results obtained at the time of the study, the computer issues on special forms, where it marks the extreme boundaries of the field of view. After that, the decoding of the results itself begins.
The central part indicates the state of the photoreceptors of the eye retinas. Doctors admit if the visual function drops out in some areas. However, if the loss is significant, then this already indicates the development of any pathology.
High intraocular pressure or migraine can be diagnosed by zones. If they do not coincide with the peripheral area, then we can safely say that the patient has these problems.
If the field of view is narrowed, then this indicates a lesion of the bundle of nerve fibers that are located in the eyeball.