Tunnel vision: when and how to get rid of?

Nature knows many examples of vision featuresin animals. Some types notice only moving objects, others perceive only certain colors. Man in this sense was lucky to get the most universal visual apparatus, although he is not without some disadvantages. For example, we have developed a so-called peripheral, or lateral, vision. Sometimes it fails. In which cases?

On the peripheral vision of man

The structure of the eye, which nature gave people,is imperfect, but it seems to be the most universal of the existing ones. A person is able to see well both near and far enough distances. The field of view is wide enough, but we can also focus on a separate object. A good perception of colors, the ability to distinguish objects with a small amount of light - all this gives reason to believe that nature generously endowed people.

Among other things, a person has andperipheral, or lateral, vision. It is less acute than central, but serves other purposes. With its help, people orient themselves in space, notice moving objects, can recognize the approaching danger, etc. This is possible due to the special structure of the retina, the cones on which are located not only in the central part, but also on the periphery, although they are much smaller. The total field of view includes up to 180 degrees horizontally and about 130 vertically. Specific values ​​vary from one person to another, in addition, this ability can be trained by doing special methods.

Tunnel vision

Under certain conditions, there is quite aa rare pathology, characterized by a sharp narrowing of the visible space. This phenomenon is called "tunnel vision", as a person may seem to be looking around as if through a pipe. As a result, serious disorientation in space can arise, in addition, such a state acts on the patient depressingly. And it arises from the fact that for some reason light only begins to perceive the central part of the retina.

When is it?

No clinic of ophthalmology will help, if not to reveal the cause of this extremely unpleasant condition. And they can be very diverse:

• oxygen starvation;
• serious hemorrhage;
• sharp pressure drop;
• hallucinogens and some other drugs;
• a sharp release of norepinephrine ("hit or run" reaction);
• nitrogen poisoning (caisson disease);
• complications of laser therapy;
• cataract;
• glaucoma;
• degeneration of the retina.

Depending on what caused the effect, tunnel vision can be either quick-passing or permanent, if it is an organic lesion of the eye.

Also, violation of the field of view can be observeddue to injuries, retinal detachment, disturbance of the conductive pathways, feeding the retina, damage to the optic nerve, etc. By the way, there is a simple test that allows you to check peripheral vision that you can conduct yourself. The subject simply stretches his arms out to the sides and moves his fingers, looking straight. Normally the movement should be seen.

How to treat?

A single scheme by which doctors act,faced with such a symptom does not exist. Everything depends on what caused the state at which tunnel vision is observed. If this is a caisson disease, the patient is placed in a pressure chamber, in the case of oxygen starvation or blood loss, the deficit is compensated.

But everything is more complicated if it is a chronicform. Fortunately, there are drugs, such as "Emoxipine", "Taufon", etc., which have a beneficial effect on the restoration of peripheral vision. In addition, lutein also helps in this matter, although it is usually not easy to completely stop the process.

Forecast

Tunnel vision is not just discomfort. A person actually loses the ability to move independently, but without experiencing this on himself, it is impossible to imagine. With proper therapy of acute condition, the negative effect quickly passes and the vision is completely restored.

If the organic lesions of the eye are gonefar away, treatment may not bring significant relief. And scientists are working to solve this problem together with doctors. Among the offered variants there are special glasses designed on the principle of binoculars, but on the contrary. This invention is not popular, because through such lenses surrounding objects seem very small, which does not improve the ability to orient in space.

There is another high-techA device that helps people suffering from disorientation due to tunnel vision. It is a camera and a tiny screen in front of the eyes of the viewer, on which the outlines of objects outside the patient's view are projected. The use of this device requires some habit, but all subjects have confirmed that with him it became much easier to navigate in space.