How can I check my vision

If you wear glasses, then, of course, you regularly visit an ophthalmologist to keep your level of vision under control.However, people who have good eyesight all their lives, the question of visiting an ophthalmologist is rare - except if you need a professional medical examination or eye diseases. Meanwhile, eyes, like other organs, need constant observation, since any deviation or disease is much easier to treat at an early stage.

When diagnostics are needed

Even with a good level of visual perception, the recommended frequency of medical examinations is 1 time per year. In other situations, full diagnostics is mandatory for the following categories:

• Persons with visual impairment. The cause of the deterioration should be clarified thoroughly, because some pathologies have similar symptoms;
• Persons using contact lenses. Lenses - a foreign body for the eye, so their incorrect or prolonged wearing can cause various pathological changes in the cornea, the beginning of which can be detected only by the physician;
• Pregnant women planning pregnancy. Since an increased eye strain occurs during labor, with the threat of retinal detachment or myopia, the ophthalmologist determines the need for measures to prevent eye damage;

vision problems

• Persons after 45-50 years.At this age, the risk of developing cataracts increases and, if necessary, treatment begins. In addition, constant monitoring of vision requires the presence of certain systemic diseases (hypertension, diabetes mellitus);
• To all children.Since the formation of the visual apparatus in a child continues until adulthood, children should be constantly examined by an ophthalmologist for timely detection and correction of deviations.

And, of course, medical examinations are necessary for trauma or illness. Self-medication or ignoring the symptoms can lead to serious complications, which will be much harder to eliminate.

Types and methods of testing the eyesight at home

If you notice that you have lost the quality of visual perception, you can use simple tests to resolve your doubts even at home.

Visometry

Everyone knows how to test the eyes with special tables. In ophthalmology the following types are used:

• Sivtseva-Golovina- a table of letters and Cyrillic alphabet;
• Landol'ta- semi-rings are used as objects;
• Orlova- a technique for studying visual acuity in children;
• The Snellen table- consists of Latin letters.

  Tables with images of optotypes that are most often used to control visual acuity

During the research, the patient is placed at a distance of 5 m from the tables, and the objects on the table are examined alternately with both eyes. Vision on different eyes can be different, like deviations. With good vision, the patient sees the lowest rows of the table.

Duo-chrome test

The test is based on the phenomenon of chromatic aberration - varying degrees of refraction of rays of different colors.For example, green rays are refracted more strongly, because they are short, but the reds are longer, therefore, their refraction is weaker. Thus, the focus of green rays is closer to the cornea than the red.And the eye, when examining green objects, acquires to a certain extent the properties of myopia, and the red ones - of hyperopia.

So in the organ of vision there are different focal lengths. They have a small range, and when the middle point, which corresponds to the yellow color, is reflected on the retina, the eyes are correctly focused.

The purpose of the duo-chrome test is to determine whether the patient has a better visual perception on a red or green background, i.e., better distinguishes painted characters.

If the subject better distinguishes objects on a green background, this means that the focus of the image is located behind the retina, and the patient needs a "plus" correction, because in this eye farsightedness. At the best qualitative perception of objects on a red background, myopia of the eye is diagnosed, and in this case correction of myopia is required for the eye.

Duo-chrome test

With the same quality of perception of objects on both sides of the table, the correct selection of glasses is diagnosed, since this survey is most often used for this purpose.

Amsler test

For the survey, the Amsler grid is used-a mesh depicted on paper, spaced on square cells and having a fat point in the center.Usually, it is used to diagnose astigmatism.

To test the vision, the subject is placed at a distance of 40-50 cm, covering one eye, since the eyes are checked in turn.When viewing the grid in patients with visual defects, the image on paper is distorted: it is possible the appearance of "holes" and spots, the curvature of lines, the falling out of the field of view of part of the object under consideration.These abnormalities are evidence of visual disturbances and require professional examination.

These surveys can be carried out at home, using ready-made tables or by making them yourself.

Clinical diagnosis

If you are not sure about the results of your home studies and still suspect a deterioration in your eyesight, Try to get an appointment with a doctor and be examined thoroughly, using traditional and innovative techniques.

Tonometry

In the normal state, the eye is filled with intraocular fluid, which is regularly updated and has a constant pressure. If the pressure rises, the eye structures may begin to deteriorate, which sometimes threatens even with a complete loss of vision.

Therefore, measurementIOP (tonometry) is one of the important methods of examination, which is mandatory for elderly patients, who are at risk for developing glaucoma.

At present, a lot of methods of tonometry and devices for its carrying out are used. In Russia, the most common is Goldman's tonometer, which is placed on the surface of the eyes alternately after preliminary anesthesia.Also there is a technique developed by Maklakov.

Tonometry of the eye

On average for an adult human IOP should not exceed 23 mm Hg. Art.

Perimetry

When looking at an object, we simultaneously perceive the surrounding objects with a lateral vision. Thislateral vision is called peripheral, and it is important for orienting a person in space.

With the development of certain diseases, peripheral vision may narrow and even disappear altogether. However, the beginning of this process, especially in the elderly, often passes by the patient's attention. DTo estimate the visual fields, the perimeter method is used,allowing to identify violations in peripheral vision and to assess the quality of central visual perception.

Computer Resverting

In practice, several perimeters are used, the most common is the Perster perimeter. In recent years, the use of the computer perimeter has become increasingly common in everyday life, allowing more reliable and accurate results.

Biomicroscopy

Examination using a slit lamp allows you to consider changes in the internal structures of the eye and, in particular, the fundus. The principle of the device is the direction of a narrow beam of light into the pupil dilated with medicines and eye examination through an optical device.

Conducting biomicroscopy of the eye

The technique is a kind of ophthalmoscopy and is one of the ways to get a quick and objective idea of ​​possible violations of the functionality of the eye structures.

Ophthalmoscopy

For ophthalmoscopy, the doctor has a special mirror, as well as a light source located on the side of the patient and slightly behind, so that it is convenient to direct the light beam into the pupil.The examination takes place in a darkened room with the additional use of a lens or without it. For convenience, the patient is previously dilated with one of the special medications (mydriatic).

Ophthalmologic examination of a child

Ultrasound

Ultrasound examination can reveal violations in the functionality of the eye structures when it is impossible to obtain an adequate result using other techniques.

Ultrasound is a safe and informative method of rapid examination, which has no contraindications for any category of patients, including pregnant, elderly and young children.

The ultrasound method allows you to obtain information about the movement inside the eye, to assess the structure of the optic nerve and oculomotor muscles, to obtain data on the normal or pathological (structures, efflorescence, tumors) of the components of the eye.

Ultrasound examination of the eye

Keratotopography

The cornea is one of the optical media of the eye, and the quality of visual perception depends on its correct shape.The change in the shape of the cornea may be due to diseases, congenital anomalies, traumas, etc. To detect such deviations at the very beginning allows the technique of obtaining a topographic map of the surface of the cornea.

Before the patient's eye, a flat disk with alternating concentric black and white circles is placed. In the center of the disk there is an aperture that allows the doctor to observe the light rays reflected from the patient's cornea from the light source behind it.When the sphericity of the cornea is disturbed in these places, the circles narrow or even merge, thus allowing to diagnose optical distortions.

Carrying out keratography

The most accurate diagnosis can be made by computer equipment using a keratograph.

OCT

Optical coherence tomography is a kind of optical biopsy that allows you to visualize various eye structures with high resolution without removing part of the tissue. The technique is based on a different speed of light reflection by different tissues.

Optical coherence tomography

Electroretinography

When stimulated by retinal light, bioelectric activity of nerve cells occurs, which may be fixed while placing an electrode on the eye surface with the simultaneous arrangement of the second electrode on the nape.To obtain a schedule for the activity of the eye structures, a special device is used. The survey is carried out in an earthed electric shielded cabin equipped for this purpose. Children under 6 years of age undergo anesthesia.

The technique allows to get an idea about the activity of cellular elements of the retina and to reveal at its earliest stages its degenerative changes. TAs a result of the examination, the doctor can determine the proportional dependence of the affected cells on the number of healthy and functioning.

Electroretinography of the eye

Electroretinography is used to diagnose various diseases of the retina in cases where Because of the clouding of the lens or the absence of visible changes in the fundus, other methods are effective.

Fluorescence angiography

Methods of investigating the vessels of the retina, choroid and optic nerve.To obtain the most complete information on the state of vascular and neural tissue of the eye in the ulnar The fluorescin sodium is introduced into the vein, a special substance that provides tissue glow when penetration. With the blood flow the drug spreads through the body and gets into the eyes.

Upon examination, a beam of light with a specific wavelength is guided into the eye, and fluorescin begins to glow.When viewed on a computer, you can see the smallest details that are inconspicuous during routine inspection.For a more detailed diagnosis, pictures are taken at the appropriate angles, after which a conclusion is made.

Fluorescence angiography of the eye

This type of examination is recommended for tumors in the choroid of the eyes, diabetes, age-related macular degeneration, disorders of blood supply to the retina, central serous chorioretinopathy.

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conclusions

Diagnosis has not done any harm to anyone, and early diagnosis is a way to avoid a lot of trouble in treating not only eye pathologies. The article lists almost all types of eye studies that allow to reveal at the early stages all possible deviations and pathologies of the internal structures of the eye, for example, the retina.