Visual acuity

Of all the senses of man, vision is perhaps the most important.

Visual acuity check

To determine visual acuity, ophthalmologists often use special tables. To check the eyes of adults, usually use the Sivtsev table, in which the rows are arranged letters, the lower, the smaller (the table with the Latin font is called the Snellen table). However, such a table does not always allow you to accurately assess visual acuity, because a person can guess the letter by shape. A more accurate, although less frequently used, is the Golovin table, consisting of rows of rings, with discontinuities in different directions. To determine visual acuity, children use tables with images of objects and animals.

Such tables usually have 12 lines, with letters or signs of different sizes, and are graded in the decimal system. Each next line corresponds to an increase in visual acuity by 0.1. Normal visual acuity is considered to correspond to the unit, in which the person quietly distinguishes the 10th row from a distance of 5 meters. Sometimes there are people with visual acuity greater than 1, able to distinguish lines below the tenth.

At the moment, in addition to the tables, technical methods for diagnosing visual acuity are also used, using special refractometers and other devices. Such methods are considered more accurate and objective.

The check is carried out separately on each eye, closing the second, as the visual acuity can be different for each eye.

Factors affecting visual acuity

Human eyesight largely depends on external factors: so in normal illumination we see better than in the dark, direct vision is often better than peripheral, again color vision works better in bright light, and black and white in the dark, which is related to the features of the structure eyes and the arrangement of cones and rods. But these factors are natural, and generally do not affect the evaluation of visual acuity per se.

But reducing visual acuity is a very common problem that can be caused by age-related changes, as well as hereditary factors, excessive eye strain, as well as due to illness or stress.

Restoration of visual acuity

Given the importance and relevance of such techniques, many methods are now being advertised that can otherwise restore visual acuity.

  1. Exercises for the eyes. Considering the strain of which the eyes are exposed daily, such gymnastics will be useful even for people who have no vision problems yet, especially since it is quite simple. Close your eyes, and gently massage them with your fingers, in circular motions. Blink 10-12 times, while squeezing as much as possible. Close your eyes and draw a look of eight or circles. Maximally lift your eyes up, then lower them down, move your eyes to the right - to the left. Gymnastics are held for 10-15 minutes several times a day.
  2. Glasses for improving visual acuity. Special glasses, opaque with small holes, used to relieve eye fatigue and improve visual acuity when the lens becomes clouded.
  3. Preparations. In the first place, such preparations include numerous vitamin complexes, LHC additives and other drugs aimed at normalizing metabolic processes in the retina and improving its functioning. Strengthen the visual acuity of these drugs will not help, but able to prevent further deterioration and stabilize the situation. Also, there are a number of drugs (used strictly according to the prescription of the ophthalmologist) aimed at relaxing the eye muscles and thus improving the blood supply to the eye.

In most cases, if visual acuity is significantly reduced, the only effective method is surgery, and the remaining methods (gymnastics for the eyes, drops, etc.) are able to give only a slight effect. However, they are an indispensable means of preventing and preventing further deterioration of vision.