Vision is priceless, so the state of the visual apparatus is checked as soon as the child is born. Again - at six months, then at three years, and at schoolchildren - annually. Adults from the age of 20, if there are no problems with the eyes, are supposed to visit an oculist every two years, after 65 years - every year. Vision monitoring reveals eye diseases on time. Especially as severe as retinal detachment, glaucoma, optic nerve atrophy, cataracts that threaten blindness.

Instruction

• Eye examination begins with an external examination of the eye apparatus. An optometrist (the more modern name of an eye specialist is an ophthalmologist) determines the condition of the eyelids, corneas, iris, pupil, etc.
• Then visual acuity is revealed. Doctors traditionally use the table Sivtseva. It is either hanging on the wall or projected on a white screen. This table consists of 12 lines of various letters: from large to very small. There is a chair six meters away. You are offered to sit down and call the letters indicated by the doctor: large, then smaller and smaller.
• First, check the visual acuity of the right eye, while you close the left eye with a manual curtain. Then vice versa. Each line is 10% of visual acuity.
• If you clearly see the letters of the tenth line on top - you have one hundred percent vision (1.0 - unit). The eleventh and twelfth lines are usually well distinguished by people with long-sightedness.
• If you see less than ten lines, the doctor selects either glasses or contact lenses. He puts on a spectacle frame with grooves in which he inserts several lenses alternately.
• The degree of vision correction with their help is determined by reading the rows of the Sivtsev table. From several options you choose the one at which the maximum number of clearly visible lines is reached.
• It is important that there is no discomfort from the designated lenses. If the eyes "cuts", they are watering, the image is "split" or there is a headache, slight dizziness, tell about it without fail. The doctor will select lenses with smaller diopters. Points should always be slightly "weaker."
• In children who cannot read, they check their eyesight or according to the table of Golovin, which shows diminishing rings with cuts in different directions, or according to the Orlova table with pictures. According to him and pick up either glasses or contact lenses.
• Ophthalmologist checks his vision near by offering to read short texts on the card, which also differ in font size. Read these lines should be, holding the card in front of you at a distance of 35 cm.
• If the vision is very weak and the patient does not even see the huge letters of the first line "W" and "B", the oculist determines the visual acuity with his fingers. He shows the patient a different number of fingers on his arm, gradually moving away from him. And the result is determined by the distance from itself to the patient.
• Modern eye clinics are equipped with electronic optical devices that determine visual acuity instantly, and not empirically, according to the tables, but automatically. To deceive them is absolutely impossible.
• There are people for whom, for example, red and green are the same thing. The oculist determines the correctness of color perception according to the atlas with color optical tests. They consist of points and circles, of which figures or geometric figures barely “look through”. The doctor offers to call them. If the patient does not see them or sees other figures and figures, then he is color blind.
• It is also very important to check the fundus of the eye. The doctor buries drops in both eyes, the pupils soon expand greatly, and he clearly sees the state of the retina, blood vessels, and macula.
• No less important is the indicator of intraocular pressure. If it is elevated, glaucoma develops. Modern automatic device pneumotonometer sent to the eyes of the exhaust air, and the pressure is measured instantly. Norm - 15-16 mm Hg. Art.
• And in the old manner, intraocular pressure is measured by a tonograph - a small cylinder, the bottom of which is painted with special paint. The tonograph is placed on the eyeball, previously treated with light anesthetic drops. The print from it is transferred to the paper in the form of a circle, and then its diameter is measured with a ruler. Norm - up to 24 mm Hg. Art.

Our vision is a valuable gift, with the help of which we can fully live and develop, feel comfortable and cozy in this colorful and big world. But sometimes our vision loses its qualities and may decline under the influence of various diseases. Therefore, it is necessary to promptly seek help from a doctor, especially if you suddenly notice that your vision has deteriorated.

A doctor who checks the quality of our vision and treats eye diseases is called an ophthalmologist or an optometrist is the same thing. Testing our vision is necessary in order to prevent diseases that can reduce the quality of vision and impair your life. The doctor examines the ability to see and distinguish objects both at large and at short distances, as well as to distinguish colors.

In general, the oculist uses special tables (such as, for example, Sivtsev's tables), maps, and alphabet, which show symbols of various heights, to check the vision. If a table with special characters is used, then it is mounted on a wall or reproduced using a projector.

The patient needs to correctly name the numbers, symbols or letters that the optometrist shows. Surely you remember when, when you visit an oculist, you are asked to cover your eye with a special sign with one hand, and, looking with the other eye, to call the letters that you see in the first or last row. Then the optometrist suggests that you close the second eye and look at the one that was closed before. So, this procedure is carried out in order to determine the sharpness of your vision on both the left and the right eye. Visual acuity in both eyes is checked this way. You do not need to do anything extra: you sit on a stool (or you can stand), and look with both eyes at the symbols, which the doctor again points out.

It is worth paying attention to the fact that if you use lenses or glasses, then the optometrist should check the visual acuity with or without glasses.

Very well, if you called and saw all the characters that the optometrist showed - in this case, the check is completed. You have beautiful eyesight. But it happens that a person calls the wrong letters, numbers and other symbols. Then the doctor prescribes a patient's refraction study. It is necessary in order to clarify the cause of reduced vision.

Refraction is the refractive power of the optical system of the eye, which is measured in diopters. Normal values ​​for the eye are 52.0-68.0 diopters.

In medical practice, it is customary to designate them with the letter D. To date, oculists have the advantage not of physical refraction, but clinical. That is, the main thing is what location occupies the main focus on the retina.

Types of clinical refraction:
  - emmetropia;
  - myopia
  - farsightedness.

Refraction is necessary if a person wears glasses or lenses.

An important role in the full vision plays and the so-called field of view. Therefore, its verification is also an important part. In the normal state, we see everything that is in front of us, that is, where our eyes are fixed. But what is on the side, blurry. This happens normally, but some patients have an altered visual field. That is, they clearly see what is in front of their eyes, but they are somehow hampered by a blur or blur, which can be observed a little higher from the “main subject” of view. Then such patients require additional testing.

  An eye test for color recognition is carried out in order to exclude a disease such as color blindness. Not all can pass such checks. But they must be passed by those who have a relative suffering from color blindness, or if the patient has pathology of the retina and optic nerve.

If we consider children's vision, then doctors use the Orlova table to check. It is similar to all tables for eye examination in adults, but has its own characteristics.

The peculiarity lies in the fact that preschool children do not know how to read, because the table shows all sorts of animals, figurines and other easily recognizable objects.

If the child is already of school age, then apply the table, which shows the letters of the alphabet. At a distance of five meters, the doctor suggests alternately closing his eyes, and call the letters. You can, of course, check your eyesight at home: for this you need to make a printout of the tables to check, put the child five meters from the table.

There are many tables for eye exams, but mostly they use the table of Sivtsev and Golovin.

“Close your right eye, now your left eye. Read the letters that I show. ” In front of the patient is a poster with the letters of the Russian alphabet drawn in black paint. Probably for most people this test seems funny, especially in childhood. However, an eye test on the ophthalmologic table is a very simple, painless, but at the same time very effective test that allows you to diagnose vision problems in a timely manner.

Sivtsev's table - this is exactly the name of the poster with the letters that is in every ophthalmologic office in Russia and the CIS countries. It is named for the ophthalmologist Dmitry Alexandrovich Sivtsev.

The test table, as is known, is a set of printing characters - letters. There are seven of them: B, I, K, M, N, Y, S. They are written in twelve lines. From the top line to the bottom of the letter are reduced.

To the left of the lines is indicated “visus” - the value corresponding to visual acuity. It is denoted by the Latin letter V and is expressed in arbitrary units. So, the row at the very top corresponds to the indicator of 0.1, the bottom one - 2.0.

It is considered a norm if a person from five meters reads written in the tenth line

A norm is considered if a person from five meters reads written in the tenth line. Then V = 1.0 (corresponds to 100% of the view). Scientists have found that such a person visually separates adjacent points when the angular distance between them is 1/60 of a degree, or 1 arc minute. At a distance of 5 m it is 1.45 mm. This distance separates two adjacent vertical segments in the letter W from the tenth row.

How is the test?

A study conducted using the Sivtsev table is called a visometry. The test fabric is illuminated by two fluorescent (daylight) lamps so that the illumination is 700 lux. The bottom edge of the illuminator is at a height of 120 cm from the floor surface.

Check the eyes alternately, first right, then left. The test eye is open, the other is covered with a special flap, but the eyelids of both eyes are open, the head is held strictly straight. Lines after the tenth are intended for people with a visual indicator of 150 and 200%. Also, these lines can be used when the cabinet length is not enough to conduct a study from 5 m. Corresponding amendments are made to the calculations.

Check the eyes alternately, first right, then left.

Visometry is performed in the following order. The doctor indicates the sign for 2–3 seconds and asks the patient to name it. Checks for adults usually begin with the bottom lines, where the smallest characters, gradually moving to the top.

Visual acuity is defined as:

• complete, when a person correctly named all the letters in the row without exception;
• incomplete (in the corresponding series), when mistakes are made, while their number is limited:

When the result is lower than 1.0, they talk about myopia (myopia), and higher than 1.0 - about hyperopia (hyperopia).

Normal vision is called emmetropia. The point of clear vision for such a person is located, as it were, in infinity, and infinity is 5 m and more. If you place the object at a shorter distance, then parallel rays are collected on the retina. For this reason, 5 m is considered optimal for visometry.

If a person is not able to read what is written in the uppermost row, they are asked to approach the table by half a meter. They do this until the person being checked correctly names all the letters or most of them. Then visual acuity is calculated using a special formula: V = d / D. Here, d is taken as the distance from which the test is performed, and D is the distance from which the line is seen in normal vision (100%, or 1.0) (this is a constant, it is indicated to the left of the rows, its indicators - from 50 to 2.5). So, if the formula multiplies the standard for such a test of 5 m per vizus index of 0.1 of the first line, then it turns out that a person can see the largest figures in the table from a distance of 50 m, the last one from 2.5 m. sees the signs of the first row, prefer the optotypes of the Pole.

Simultaneously with Sivtsev's table, a table is usually used, named after another ophthalmologist, Sergey Selivanovich Golovin. He composed her of Landolt rings (rings broken on one side), arranged in twelve lines.

The size of the rings is determined as follows: 7 mm divided by the value of V (the same indicators as in the Golovin table) corresponding to this row. As a result, the first line contains rings of 70 mm, on the bottom - 3.5 mm.

The principle of determining the indicator is similar to the previous one.

How to check the sight of children

Not all preschool children know the alphabet, so the Orlova or Aleinikova tables are used for them. The standard 12 lines consist of pictures, not letters, and several Landolt rings. The size of the figures is determined by the same formula as the size of the Landolt rings for the Golovin table.

Inspection of the child has its own characteristics. For a more reliable result, the doctor before the procedure should explain to the child what they want from him, and make sure that the child is able to name the figures depicted. To do this, they bring him to the test canvas and ask him to say what he sees there.

Children get tired very quickly, so the optometrist begins to show the largest pictures, only one of each row. Only when the child is unable to give the correct answer, he is shown the remaining characters from the same series.

Pole Optotypes

They are used to determine from what distance a person can read the characters of the first row, that is, when his visual acuity is lower than 0.1.

These optotypes are a set of circular and trilinear signs. They are designed so that by the thickness of the lines and the width of the gaps it is possible to determine the visual acuity in the range from 0.04 to 0.09. The study is conducted with a standard 5 m.

This table is considered the most common in the world. It traditionally received its name from the ophthalmologist who created it in 1862 - the Dutchman Hermann Snellen. It consists of capital Latin letters-optotypes, which are reduced from one line to another.

The largest optotypes are at the top. A person, having 100% of sight, freely recognizes signs in 1–8 rows. The maximum distance from which the top row is visible is 60 m, the last one is from 5 m. The distance between a table and a person is 6 meters.

How to do visometry yourself?

You can make the Sivtsev table yourself, so that if you have any doubts, check your eyesight. This will require three white matte sheets of A4 paper, a laser printer, a black marker, felt-tip pen or ink, as well as adhesive tape, glue.

Here is a guide to create it.

1. It is necessary to download files located (files are attached in PDF format) and print them on paper. It is important to ensure that the scale was 100%. For a more accurate result, the paper should be pure white, without a yellowish tint.
2. It often happens that the printer does not give a uniform black color. Then a black marker or mascara will come in handy: they let the characters down to increase the contrast.
3. To connect the printed sheets using glue or tape.
4. The finished table is attached to a wall or other vertical surface — it could be a door, a cabinet surface, and the like. Height must be calculated so that the tenth row is exactly at eye level.

To check if there are any distortions in the printout, it is enough to measure the letters. They are inscribed in a square with a side of 70 m - for the first row, 35 mm - for the second, 7 mm - for the tenth.

The result is affected by the degree of illumination of the room, depending on the time of day and weather. For uniform illumination use a table lamp with a power of 40 W, the rays of which are directed to the table.

Measuring visual acuity, do not worry if some day the result will be worse. This happens after stress or grueling work. In order for everything to return to normal, you need to have a good enough rest or calm down.

Devices are replacing

Recently, replacing the tables come transparency devices. The test mark is depicted not on paper, but on milky glass. Behind the glass is a light source. Oculists use collimator method in their work. Then the letter or sign is close, but thanks to the optical instruments they are seen in infinity. In clinics, you can now see special projectors, the feature of which is good illumination and clear, high-contrast image transmission.

Video - T table types for vision testing and its improvement