Usually, an ophthalmologist’s appointment is associated with letter tables. It is with their help that doctors perform visometry – checking visual acuity. Our clinic uses various methods to study visual acuity in adults and children.

What is visual acuity

Visual acuity is understood as the ability to distinguish between two luminous points at a minimum angle. If your eye sees them at an angle of 1 minute, visual acuity is considered normal, equal to one. It is interesting that in ancient times, the ability to see the double star Ursa Major in the night sky was considered ideal for warriors. Since then, the assessment tools have changed, but the benchmark has remained the same. Our doctors will help you become as sharp-sighted as Roman soldiers.

Research tools

For visometry , alphabetic or symbolic tables are used. Most often in the ophthalmologist’s office you will see a Sivtsev table with Cyrillic letters or a Golovin table with half rings.

For an accurate assessment, it is important to comply with a number of conditions:

• Maintain a certain distance to the table. In Russia it is 5 meters. When measuring near vision, the table is placed at a distance of 33 cm from the eyes.
• The light source should be only on the table itself. Optimal illumination is 700 lux .

The slightest deviations, additional light with the standard method of verification distort the result. We use special sign projectors for which it is not necessary to comply with these conditions. Therefore, the test can be carried out from any distance and in any light.

Today, the Internet offers a visual acuity test on its own online. Since it is difficult for you to maintain the optimal distance and light level at home, the result of such a measurement will be incorrect.

How is visometry

First of all, visometry is carried out in a relaxed state, since stress and overwork affect the result.

The visual acuity of each eye is measured separately. The patient sits at a certain distance from the table, closes one eye and reads the signs.

If you see the third line from the bottom, you have single vision. Some patients, due to the anatomical features of the eye, are able to distinguish characters in the penultimate and last lines. This corresponds to the values 1.5 and 2. When choosing an optical correction, binocular vision is assessed: the patient reads signs simultaneously with both eyes.

What is the difference between visometry in the visually impaired

If the patient is not able to distinguish the signs of the table, we check visual acuity by counting fingers. The subject names the number of fingers that he sees in front of him.

If this method is not suitable, use the method of light perception . A person must determine from which side the light comes.

How children’s eyesight is tested

Our doctors use behavioral techniques when working with babies. In the smallest, ophthalmologists check the reaction to bright light.

At the age of 3-5 months, the gaze of babies is already focused. Therefore, for research, we use bright objects, for example, a ball. By the diameter of the ball that the child notices, the ophthalmologist determines how well the baby sees. From the age of three, when children speak and know the names of objects and animals, they use special tables with understandable symbols.

Sometimes the baby’s gaze does not focus on the subject. While it is not clear what the problem is, doctors use special techniques. For example, instead of a ball, the subject is shown a lattice or a chessboard. If the doctor sees the movements of the pupil across the field, then the baby distinguishes the structure of the object. Another version of the special vision test is based on the fact that children prefer to look at structured objects. Therefore, the eye of a seeing child is attracted by a striped object, and not a uniformly colored one.

How to decipher the results

In Russia, visual acuity is expressed as a decimal fraction. Normal is 1.0 for each eye. A result of 0.9 indicates a slight decrease in visual acuity, which usually does not require optical or laser correction . In this case, the doctor may advise eye exercises, give general recommendations regarding nutrition and lifestyle.

With a significant deterioration in vision, we conduct a comprehensive diagnosis and determine the cause of the changes. Based on the examination, our doctors select the best ways to correct vision: hardware therapy or laser treatment.

We recommend that you visit an ophthalmologist every year, even if you do not have any complaints.