Tables and tests for vision testing

Correction of vision is performed after a thorough examination of visual acuity by an ophthalmologist.How is vision checked? What are the ways today for this? Is it possible to conduct a vision test yourself?

We will try to answer all of these and other questions in the article below.

Why do I need a vision test?

Vision is checked in the office of an ophthalmologist.Now in many salons of optics there is a specialist's office equipped with modern diagnostic equipment.

The vision test includes a survey of the ability to distinguish detail of the image near and at large distances, the field of view (determining its defects) and the ability to distinguish colors.

To test vision use letters or special characters of different sizes.These icons are depicted on special tables that hang on the wall, or project onto the screen using a special device - a projector of signs.The patient is required to identify the symbols shown to him. Visual acuity is checked first for each eye separately, and then for the two eyes (ie when see simultaneously with two eyes), and with corrective lenses (if you wear glasses or contact lenses) and without them.To test the severity of near vision, as a rule, offer to read small fragments of text written in letters of varying sizes.

If, as a result of checking the visual acuity, it is determined that the vision is below the norm (the visual acuity equal to, for the norm is accepted), then the oculist will further investigate the causes of this decrease (refraction).

The study of patient refraction is the determination of the optical power of the corrective spectacle lenses, which are required for the patient in order to increase his visual acuity.

Refractive errors occur when light rays are collected not exactly on the retina, but before or behind it.Refraction is always investigated in those who already wear glasses or contact lenses. The standard procedure for checking eyesight is to determine visual acuity and refractive errors.

How often should I check my visual acuity?

Visual acuity needs to be checked regularly.If there are no problems with vision, then depending on the age, it is recommended to check eyesight after certain periods:

• after birth;
• about 6 months;
• in 3 years;
• before school and at school every year;
• every 2 years between the ages of 19 and 64;
• every year after 65 years.

Visual acuity is checked for the following purposes:

• to check if vision correction is required;
• for monitoring of possible eye diseases (for example, retinal detachment in diabetes);
• with trauma to the eye;
• for obtaining a driver's license or admission to certain professions.

How to prepare the patient for visual acuity check?

To check the vision, special training is not required. But some recommendations still exist:

• If you use glasses or contact lenses, then take them with you.
• Take a prescription for glasses or contact lenses written before to you.
• Some medications can affect your eyesight, so tell the specialist about all the medications you use.
• Try to explain to the oculist what your vision problems are, what you experience discomfort symptoms and in what situations.

Tables and tests

There are several tables for testing visual acuity. They are similar in many respects, but differ only in some nuances.

Sivtsev's table

Sivtsev's table is a special template - a set of printed characters.It contains two columns: on the left - "D (the distance in meters from which this sign is seen by a person with 100% vision), on the right - "V (visual acuity if this number of characters is read from 5 meters). The values ​​of V correspond to the visual acuity examined from a distance of 5 meters. Normal vision is equal to,.

According to the Sivtsev table, you can check the visual acuity yourself.

To do this, hang a sheet with a printed test on the wall at eye level, turn on the general lighting in the room, Go to a distance of 5 meters from the dough, close your palm with one eye and read the lines that you see.Do the same procedure with the second eye, correlate the results.

The Snellen table

The Snellen table is one of the first instruments to test visual acuity, which was developed in 1862 by the Dutch ophthalmologist H. Snellen. Today, it has found wide application in the US and is an American analogue of the Sivtsev table.

The Snellen table consists of lines with capital letters (optotypes). The size of the characters gradually decreases from the top to the bottom line.The largest letters are in the top row of the table. A person with 100% vision can easily name them from a distance of 20 feet (about 6 meters). On the first line is one very large letter. It can be E, H, N or A. The traditional Snellen table for checking eyesight is issued with 11 lines of printed letters.

The principle of verification for this table is the same as with the Sivtsev pattern: the lowest row, which could be accurately recognized, shows visual acuity. The norm is 6/6; a person should read one of the last lines from a distance of 6 meters.

In determining the visual acuity of the Sivtsev table, the patient should be in good health. Start the vision test with the symbols of the top line, do not tilt your head and do not grumble.

The given table is intended for children and represents lines with pictures which size decreases from a line to a line in a direction from top to down. To the left is indicated the distance D (in meters) from which a child with normal vision should see them (50 meters for the upper row, meter for the lower row).On the right is the value V is the visual acuity when recognizing pictures from a distance of 5 meters (if the eye sees only the upper row, if the bottom row is visible).Normal vision (,) - when the child sees with every eye from a distance of 5 meters the tenth line.

To check the vision according to Orlova's table at home, hang a sheet with a printed test on the wall at the eye level of the child, turn on the total lighting in the room, step away at a distance of 5 meters from the dough, cover one child's eye with a sheet of paper and ask him to read the lines he sees.Do the same procedure with the second eye of the child, correlate the results.

Orlova's table for vision testing in children

If a child from 5 meters does not recognize the signs of the upper row, he is approached to the table and every, one meter is asked, until he calls correctly the signs of the upper row.

Take care that the child does not tilt his head or squint.

Golovin's Table

Table Golovin - a standard set of optotypes to determine the contrast of human vision.It consists of a combination of four different rings with a gap equal in width and height. The table contains two columns: on the left - "D (the distance in meters from which this sign is seen by a person with good eyesight), on the right - "V (visual acuity if this number of characters is read from 5 meters). The values ​​of V, shown in the right column of the table, correspond to the visual acuity examined from a distance of 5 meters.Normal vision is,. The essence of the test in checking the ability to distinguish from a distance breaks in the rings.

To check the vision according to the Golovin table at home, hang a sheet with a printed test on the wall at eye level, turn on the general lighting in the room, move 5 meters from the dough, close one eye with your palm and read the lines, which you see.Do the same with the second eye. Correlate the results.

Golovin's Table

The Star of Siemens

This test is designed to identify astigmatism.In the normal state, the cornea and the lens of the healthy eye have an even spherical surface. With astigmatism, their shape is impaired. Instead of a normal image, a person with astigmatism sees a distorted picture, in which some lines are clear, others - blurred. AStigmatism is a common cause of poor vision, it often accompanies myopia and hyperopia.It is corrected, as a rule, by glasses, contact lenses or surgically.

In the figure, all the lines are the same color and same width. The Star of Siemens allows you to observe how visual acuity is constantly changing, and these changes are partly subject to control.

If the clearness of vision is normal, then, not reaching the center, the rays spread out and begin to overlap.On a short section, they can merge with the background. As you move further toward the center, the rays are again clearly visible.The image turns into its negative. In place of the black ray is a white background, and in place of a white background - a black ray. In the course of the rays, such an inversion can occur several times. People with good eyesight can observe this effect if they bring the picture very close to the eyes. At a great distance from the picture, the rays for them will merge into a solid gray mass.

To test the vision for the star of Siemens home include general lighting in the room, close one eye and look at the lines. Do the same with the second eye.

The Star of Siemens

A duo-chrome test for determining myopia and hyperopia

This test will help to determine what your vision is: myopia (-), farsightedness (+) or emmetropia (ie norm).

To test the vision for this test, turn on the general lighting in the room, close one eye with the palm of your hand and read the letters on both sides of the table. Do the same with the second eye.

With normal vision, the eye sees the letters on both sides the same.If the symbols seem clearer to you on a red background, then there is a high probability that you have nearsightedness; if on the green - farsightedness.If you find that the results do not correspond to the norm, consult an ophthalmologist.

A duo-chrome test for determining myopia and hyperopia

Amsler test

The Amsler test is designed to detect pathologies of the central area of ​​the retina. For testing, put on glasses or contact lenses (if you usually wear them), turn on the general lighting in the room, close one eye with your palm and look at the lines in the table. Focusing on the central point, evaluate the rest of the grid. Do the same procedure with the second eye, correlate the results.

During testing, you need to be in good health. You can not squint and tilt your head. The image should be placed at a distance of 30 cm from the eyes.

Answer for yourself the following questions: Are all lines even? Are all squares of the same size? Are there any gray spots and curved lines? If all the answers are negative, then your macular (central) area of ​​the retina is normal. If you find that the results do not correspond to the norm, consult an ophthalmologist.

Amsler test

Color blindness test (color perception)

Daltonism is the lack of the ability to correctly identify one or more colors.Most people do not see red, green, blue or yellow colors. This pathology is congenital. Color blindness tests will identify this disease.

To verify the vision of color perception, special polychromatic tables are used, the author of which is E. B. Rabkin.Each table has a large number of colored dots and circles. They are the same in brightness, but not in color.A person with normal vision sees figures on them, "color-blind" or does not see anything, except points and circles, or sees the wrong figures that are depicted. There are many different types of this pathology.Determine its presence can also be at home in the tables of Rabkin.

Test for color blindness

What tables are checked by drivers?

To obtain a driver's license, the candidate must check the eyesight of the oculist.The test for color blindness is performed by a doctor using the Sivtsev table.Sometimes, in addition to it, the Golovin table can be used. The visual acuity of the "best" and "worst" eyes is determined. If it does not comply with accepted standards, a future driver needs to solve the problem of vision correction with glasses, contact lenses or a surgical procedure.

Video

conclusions

So, a vision test is a necessary procedure for all, which must be repeated periodically. This can be done using the tables mentioned above. They can be downloaded from the Internet and printed to check their eyesight at home. If a problem is found, the examination in the ophthalmologist's office should be repeated. Only such results will be reliable, and if eye diseases are detected, the doctor will prescribe the necessary treatment, select the optimal means of vision correction.