What is binocular vision: how to check and restore. Basic verification methods

Use a device designed by the Tochmedpribor plant or a similar test projector of test marks. The operation of the device is based on the principle of dividing the fields of vision of both eyes using color filters.

The removable cover of the device has four holes with light filters arranged in the shape of a lying letter “T”: two holes for green filters, one for red and one for white. The device uses light filters of complementary colors; when placed on top of each other, they do not transmit light.
The study is carried out from a distance of 1 to 5 m. The subject is wearing glasses with a red filter in front of the right eye and with a green filter in front of the left eye.

When examining the colored holes of the device through red-green glasses, a subject with normal binocular vision sees four circles: red on the right, two green ones vertically on the left, and a middle circle, as if consisting of red (right eye) and green (left eye) colors.

• If there is a clearly defined dominant eye, the middle circle is painted in the color of the light filter placed in front of this eye.
• With monocular vision of the right eye, the subject sees through the red glass only red circles (there are two of them), with monocular vision of the left eye - only green circles (there are three of them).
• With simultaneous vision, the subject sees five circles: two red and three green.

Raster haploscopy (Bagolini test)

Raster lenses with the thinnest parallel stripes are placed in the frame in front of the right and left eyes at an angle of 45° and 135°, which ensures mutually perpendicular direction of the raster stripes, or ready-made raster glasses are used. When fixing a point light source placed at a distance of 0.5-1 cm in front of the glasses, its image is transformed into two luminous mutually perpendicular stripes. With monocular vision, the patient sees one of the stripes, with simultaneous vision, two unaligned stripes, with binocular vision, the figure of a cross.

According to the Bagolini test, binocular vision is recorded more often than according to the color test, due to the weaker (non-color) separation of the right and left visual systems.

Chermak's method of sequential visual images

They evoke successive images by illuminating the right and left eyes alternately while fixing the central point: with a bright vertical stripe (right eye), and then with a horizontal stripe (left eye) for 15-20 s (with each eye). Next, successive images are observed on a light background (screen, sheet of white paper on the wall) with light flashes (after 2-3 s) or when blinking the eyes.

By the location of the stripes of foveal visual images in the form of a “cross”, the misalignment of the vertical and horizontal stripes, or the loss of one of them, one judges, respectively, their combination (in persons with binocular vision), misalignment with the same or cross localization, suppression (suppression of one image), presence of monocular vision.

Assessment of binocular functions using a synoptophore

The device performs mechanical haploscopy using two separate movable ones (for installation at any angle of strabismus) optical systems- right and left. The set consists of three types paired test objects: for combination (for example, “chicken” and “egg”), for fusion (“cat with a tail”, “cat with ears”) and stereotest.

The synoptophore allows you to determine:

• ability for bifoveal fusion (when both images are combined at a strabismus angle);
• the presence of a zone of regional or total suppression (functional scotoma), its location and size (according to the measuring scale of the device in degrees);
• the amount of fusion reserves according to tests for fusion - positive (with convergence), negative (with divergence of paired tests), vertical, torsion;
• presence of stereo effect.

Synoptophore data allows you to determine forecast and tactics complex treatment, and also choose the type of orthoptic or diploptic treatment.

Depth Vision Assessment

A Howard-Dolman type device is used. The study is performed in natural conditions without dividing the field of view.

Three vertical poibor rods (right, left and movable middle) are placed in the frontal plane on one horizontal straight line. The subject must perceive the displacement of the middle rod as it approaches or moves away in relation to the two fixed ones. The results are recorded in linear (or angular) quantities, components for persons mature age 3-6 mm for near (from 50.0 cm) and 2-4 cm for distance (from 5.0 m), respectively.

Depth vision is well trained in a real environment: ball games (volleyball, tennis, basketball, etc.).

Stereoscopic vision assessment

• Using the flying fly test. The study is carried out using a booklet with polaroid vectograms (fly-test from Titmus). When viewing the picture through the Polaroid glasses supplied with the booklet, you get the impression of a stereoscopic effect.
  Based on the recognition of the location and degree of distance of tests with different levels of lateral displacement of paired drawings, the threshold of stereoscopic vision is judged (from the presence of the ability to stereoscopic sensation to 40 arc seconds), using the booklet table.
• Using the Lang test. The study is carried out on a Polaroid booklet using Polaroid glasses, similar to the method described above. The method allows one to estimate the threshold of stereoscopic vision in the range from 1200 to 550 arc seconds.
• On a lens stereoscope with paired pictures of Pulfrich. Paired pictures are built according to the principle of transverse disparity. The details of the drawings (large, small) make it possible to register the stereoscopic vision threshold of up to 4 arc seconds based on the correct answers of the subject.
• Screening methods. Research is carried out using test mark projectors equipped with a measuring ruler for special tests (Carl Zeiss). The test consists of two vertical lines and a round luminous spot under them. A subject with stereoscopic vision, when viewed through Polaroid glasses, distinguishes three figures located at different depths (each of the strokes is visible monocularly, the spot is visible binocularly).

Definition of phoria

Maddox test

The classic technique involves using a red Maddox “stick” from a set of lenses, as well as a Maddox “cross” with a vertical and horizontal measuring scale and a point light source in the center of the cross. The technique can be simplified if you use a point light source, a Meddox “wand” in front of one eye and a prism ophthalmic compensator OKP-1 or OKP-2 in front of the other eye.

The ophthalmic compensator is a biprism of variable strength from 0 to 25 prism diopters. At horizontal position When using the rod, the examinee sees a vertical red stripe, displaced in the presence of heterophoria from the light source outward or inward in relation to the eye in front of which the rod is placed. The strength of the biprism, which compensates for the displacement of the strip, determines the amount of esophoria (when the strip is displaced outward) or exophoria (when displaced inward).

A similar research principle can be implemented using test mark projector tests.

Graefe's test

Draw a horizontal line with a vertical arrow in the middle on a piece of paper. A prism with a strength of 6-8 prism diopters is placed in front of one eye of the subject with the base up or down. A second image of the drawing appears, shifted in height.

In the presence of heterophoria, the arrow moves to the right or left. A displacement of the same name (outward) in relation to the eye in front of which the prism is placed indicates esophoria, and a cross displacement (inward displacement) indicates exophoria. A prism or biprism, which compensates for the degree of displacement of the arrows, determines the magnitude of the phoria. Tangential markings can be applied to the horizontal line with dots corresponding to degrees or prism diopters (instead of biprism). The degree of displacement of the vertical arrows on this scale will indicate the magnitude of the phoria.

Binocular vision testing can be done different methods, among which the generally accepted method is research using a 4-point color test (test with a color device).

The subject observes 4 multi-colored circles (2 green, white and red), glowing through filter glasses (with one red and one green glass). The color of the circles and lenses are selected in such a way that one circle is visible only with one eye, two circles - only with the second, and one circle (white) is visible with both eyes.

The patient sits at a distance of 5 m from a direct and strong light source. He puts on filter glasses: the right eye is covered with red glass, and the left eye with green glass. Before starting diagnostic procedures, check the quality of the filters. To do this, cover the eyes one by one with a special shield, and the patient first sees two red circles with his right eye, and then three green circles with his left eye. The main examination is carried out with the eyes open at the same time.

There are three types of examination results: binocular (normal), simultaneous and monocular vision.

Sokolov's method (1901)

The method is that the patient is asked to look into a tube with one eye (for example, a sheet facing into a tube), and a palm is applied to its end on the side of the open eye. In the presence of binocular vision, the impression of a “hole in the palm” is created, through which the picture that is visible through the tube is perceived. This is because the picture seen through the hole in the tube is superimposed on the image of the palm in the second eye.

With simultaneous vision, the “hole” does not coincide with the center of the palm, and with monocular vision, the “hole in the palm” phenomenon does not appear.

The experiment with two pencils (they can be replaced with ordinary sticks or felt-tip pens) is of approximate value. The patient should try to align the tip of his pencil with the top of the pencil in the doctor's hands so that a clearly straight line is formed. A person with binocular vision easily performs tasks with both eyes open and misses when one eye is closed. In the absence of binocular vision, misses are noted.

Other, more complex methods (prism test, Bogolin striped glass test) are used.

Strabismus according to the Hirschberg method

The magnitude of the strabismus angle is simply and quickly determined by the Hirshberg method: a beam of light is directed into the eyes of the subject and the location of light reflexes on the cornea is compared.

The reflex is recorded in the eye and observed near the center of the pupil, or coincides with it, and in the eye that squints, it is determined in the place corresponding to the deviation of the visual line.

One millimeter of its displacement on the cornea corresponds to a strabismus angle of 7 degrees. The larger this angle, the further the light reflex moves from the center of the cornea. So, if the reflex is located at the edge of the pupil with its average width of 3-3.5 mm, then the angle of strabismus is 15 degrees.

A wide pupil makes it difficult precise definition the distance between the light reflex and the center of the cornea. More accurately, the angle of strabismus is measured on the perimeter (Golovin’s method), on a synoptophore, using a test with covered prisms.

Subjective method for determining binocular vision

To determine the level of refraction of light in the eyes using a subjective method, you need a set of lenses, a trial spectacle frame and a table for determining visual acuity.

The subjective method for determining refraction consists of two stages:

• determination of visual acuity;
• applying to a rimmed eye optical lenses(first +0.5 D and then -0.5 D).

With emmetropia, positive glass worsens Visus, and negative glass first worsens it, and then does not affect it, since accommodation is activated. With hypermetropia, “+” glass improves Visus, and “-” glass first worsens, and then, with a large accommodation stress, it is not displayed on Visus.

In young patients with visual acuity equal to one, two types of refraction can be assumed: emmetropia (Em) and mild hypermetropia (H) with the participation of accommodation.

In elderly patients with visual acuity of “one”, only one type of refraction can be assumed – accommodation is weakened due to age.

When visual acuity is less than one, two types of refraction can be assumed: hypermetropia ( high degree, accommodation cannot help) and myopia (M). In hypermetropia, a positive glass (+0.5 D) improves Visus, and a negative glass (-0.5 D) worsens Visus. In myopia, a positive glass worsens visual acuity, and a negative glass improves it.

Astigmatism ( different kinds refraction in different meridians of one eye) is corrected by cylindrical and sphero-cylindrical lenses.

When determining the degree of ametropia, the glass changes for the better. Visus with it (1.0).

Moreover, with hyperopia, refraction determines the largest positive glass, with which the patient sees better, and with myopia, the smaller negative glass, with which the patient sees better.

The different type or degree of refraction of both eyes is called anisometropia. Anisometropia up to 2.0-3.0 D in adults and up to 5.0 D in children is considered tolerable.

Objective methods for determining binocular vision

Skiascopy (shadow test), or retinoscopy – objective method determination of eye refraction. To carry out the method you need: a light source – a table lamp; mirror ophthalmoscope or skiascope (concave or flat mirror with a hole in the middle); skiascopic rulers (this is a set of cleaning or diverging lenses from 0.5 D-1.0 D in ascending order).

The study is carried out in a dark room, the light source is located to the left and slightly behind the patient. The doctor sits 1 m away from him and directs the light reflected from the skiascope into the eye being examined. In this case, a light reflex is observed in the pupils.

By slightly rotating the handle of the glass, the reflected beam is moved up and down or left and right, and through the opening of the skiascope, the movement of the skiascope reflex in the pupils is observed.

Thus, skiascopy consists of 3 points: obtaining a red reflex; obtaining a shadow, the movement of which depends on the type of mirror, the distance from which it is examined, and the type and degree of refraction; neutralizing the shadow using a skiascopic ruler.

There are 3 possible variants of the skiascopic reflex (shadows against the background of the red reflex):

• the skiascopic reflex moves in accordance with the movement of the mirror;
• it moves opposite to the movement of the mirror;
• there is no shadow against the background of the red reflex.

If the movement of the reflex and the mirror coincide, we can talk about hypermetropic vision, emetropic or myopic to one diopter.

The second option for moving the skiascopic reflex indicates myopia of more than one diopter.

Only with the third variant of the reflex movement do they conclude that myopia is one diopter and measurements are stopped at this point.

When examining an astigmatic eye, skiascopy is performed in two main meridians. Clinical refraction is calculated for each meridian separately.

In other words, binocular vision can be examined different ways, everything directly depends on the severity of the symptoms, on the patient’s complaints and on the professionalism of the doctor. Remember, strabismus can only be corrected by early stages development and this will take a lot of time.

Before studying binocular vision, a test is performed with covering the eye (“carpet test”), which makes it possible to establish with a high probability the presence of obvious or hidden strabismus. The sample is made as follows. The person conducting the study sits opposite the patient at a distance of 0.5-0.6 m from him and asks the patient to look intently, without blinking, at some distant object located behind the examiner. At the same time, he alternately covers either the patient’s right or left eye with his hand or an opaque screen without intervals.

If at the moment of opening neither eye makes movements, then most likely there is no strabismus; if there is movement, then there is strabismus. If the movement of the eye when opening (transferring the shutter to the other eye) occurs towards the nose, then the strabismus is divergent, if towards the ear it is convergent, i.e., the opposite angle of the strabismus. These eye movements are called adjustment movements. To determine the nature of strabismus (hidden or obvious), first one and then the other eye is closed and opened. In the case of obvious strabismus, when opening one of the eyes (leading), both eyes make a quick adjustment movement in one direction, and when opening the other eye (squinting), they remain motionless. In the case of hidden strabismus (heterophoria), when each eye opens, a slow (vergence) movement of only that eye occurs.

The actual study of binocular vision includes determining the nature of vision (with two eyes open), studying muscle balance (phoria), aniseikonia, fusional reserves, and stereoscopic vision.

Determination of the nature of vision. The presence or absence of binocular vision is determined using the “four-point test”. This test was proposed by the English ophthalmologist Wars. The subject observes 4 glowing circles different color through filter glasses. The colors of the circles and lenses are selected in such a way that one circle is visible to only one eye, two circles are visible only to the other, and one circle (white) is visible to both eyes.

We produce a color test device TsT-1. The round lantern, the front wall of which is covered with a black lid, has 4 round holes arranged in the shape of a letter “T” turned to its side: the top and bottom are covered with green filters, the right one is covered with red, and the middle one is covered with colorless frosted glass. The flashlight is hung on the wall next to the table or screen to study visual acuity.

82. Color test TsT-1 - a device for studying binocular vision. 3 - green; K - red; B - white.

There are three possible test results: binocular (normal), simultaneous and monocular vision. At the same time, simultaneous is also divided into various types of strabismus, and monocular has two options depending on the dominant eye.

Table 6. Interpretation of the results of the color test study

The study of phoria is carried out as follows. The patient puts on a trial frame with lenses that completely correct ametropia. A Maddox cylinder is inserted into one of the sockets (usually the right one) in a horizontal position of the axis, and a prismatic compensator with vertical position handles and zero position of marks on the scale. The subject is asked to look at a point source of light located at a distance of 5 m from him, and he must indicate on which side of the light bulb there is a vertical red stripe.

If the stripe passes along the light bulb, then the patient has orthophoria, if to the side of it - heterophoria. Moreover, if the stripe passes on the same side of the light bulb on which the Maddox cylinder is located, then the patient has esophoria, if on the opposite side, then exophoria. To determine the degree of heterophoria, rotate the compensator roller (or change the prisms in the frame) until the strip intersects the light bulb. At this moment, the division on the compensator scale will indicate the amount of heterophoria in prism diopters. In this case, the position of the prism with the base towards the temple indicates esophoria, and with the base towards the nose – exophoria.

Since subjects have a tendency to self-compensate for heterophoria, it is recommended to cover the eye against which the Maddox cylinder is located with a shield and record the position of the strip only at the first moment after its opening.

After determining the horizontal phoria, the vertical one is examined. To do this, the Maddox cylinder is positioned with its axis vertical, and the prismatic compensator is positioned with the handle horizontally. When examining, make sure that the horizontal red stripe intersects the light bulb.

There are other ways to determine heterophoria, in which the separation of the visual fields of the two eyes is not as complete, for example, when studying using filters of additional colors, the so-called color anaglyphs. This is the Schober test. Using a projector, the patient is shown two concentric green circles with a red cross in the center.

83. Schober test for studying heterophoria.

Using a prism compensator or prisms from the set, the cross is moved to the center.

In this case, the bases of the prisms should be facing in the direction where the image of a given eye is shifted.

The value of heterophoria measured using the Schober method is usually somewhat less than when determining it using the Maddox method, since in this case the separation of the visual fields of the right and left eyes is incomplete; the subject sees with both eyes the screen and objects located around it.

The less completely the division of visual fields is made, the lower the value of heterophoria. In some countries, a method for studying binocular balance with minimal field separation—fixation disparity—has become widespread.

Field separation is accomplished using Polaroid filters placed in front of the eyes. The subject observes a screen on which there are signs (letters or numbers) visible with both eyes on the periphery of the field and a horizontal stripe in the middle of the field. In the middle of this stripe there are two vertical luminous marks, covered with Polaroid glasses, that is, visible separately to the right and left eyes.

84. Test for studying fixation disparity.

Fixation disparity is measured repeatedly by applying various prisms (rotating the prism compensator) with the base to the nose and temple. By its size (no more than 30") and resistance to the “load” of prisms, the stability of binocular vision is judged.

Study of fusion reserves. Fusion reserves are examined using a synoptophore, or prismatic compensator.

A synoptophore is a device for the diagnosis and treatment of binocular vision disorders, mainly with strabismus. It is equipped with two movable heads, each of which contains a light source, a system of mirrors and lenses, and a socket for a slide.

85. Synoptophore.

The heads can move along an arc and also rotate around their axis. Thus, the angle between the visual lines of the two eyes can vary from +30° to -50°. Consequently, with strabismus, it is possible to project similar objects to the two eyes onto the central fovea of ​​the retina and cause their fusion.

Synoptophore slides contain three groups of objects:
1) objects for combination that do not have common elements, for example, an egg and a chicken, a garage and a car, a circle and a star inscribed in it;
2) objects for merging, which are silhouette figures with a large central common element, for example, two cats, one of which has ears but no tail, and the other has a tail but no ears;
3) objects in stereopsis - two similar pictures, in one of which some of the details are shifted horizontally; when merging, this creates the effect of disparity and reproduces a sense of depth - some details are visible closer to the person being examined, while others are further away from him.

Objects of the 1st group are used to determine phoria, and in the presence of strabismus, its angle. Objects of the 3rd group are used for research and training of stereo vision. Objects of the 2nd group are used to study the ability to fusion and fusion reserves.

To determine fusion reserves, slides of the 2nd group, for example “cats”, are installed in the heads of the synoptophore. Place the heads at position 0 on the arc scale. The subject is asked if he sees one cat with a tail and ears. If he doesn’t see, then slides of the first group are introduced, for example with the image of a chicken and an egg, and the heads are moved in an arc until the chicken is in the center of the egg.

If the answer is yes, then they begin to slowly move the heads in an arc towards each other until the subject begins to notice a split in the picture: instead of one cat, two appear. The sum of the divisions on which the heads are located at this moment will indicate a positive fusion reserve.

Fusional reserve, like phoria, can be measured in degrees and prism diopters.

Fusion reserves are measured using a prism compensator as follows.

The subject, wearing a trial frame, with prismatic compensators inserted into both sockets (with the handle in a vertical position), observes from a distance of 5 m a vertical black stripe on a white background. Rotate the roller of both strip compensators. At this point, the sum of the divisions on the scales will indicate a positive fusion reserve. Then the rotation of the prisms is repeated with the bases towards the nose, i.e. towards each other. The moment the band splits will indicate the negative fusion reserve in prismatic diopters.

Approximate norms of fusion reserves: 40-50 prdptr (20-25°) - positive, 6-10 prdptr (3-5°) - negative.

Yu.Z. Rosenblum

Binocular vision provides a three-dimensional perception of the surrounding world in three-dimensional space. With the help of this visual function, a person can cover with attention not only the objects in front of him, but also those located on the sides. Binocular vision is also called stereoscopic vision. What are the consequences of a violation of stereoscopic perception of the world, and how to improve visual function? Let's look at the questions in the article.

Feature of stereoscopic perception of the world

What is binocular vision? Its function is to provide a monolithic visual picture by combining the images of both eyes into a single image. A feature of binocular perception is the formation of a three-dimensional picture of the world with the determination of the location of objects in perspective and the distance between them.

Monocular vision is capable of determining the height and volume of an object, but does not provide an idea of ​​​​the relative position of objects on a plane. Binocularity is a spatial perception of the world, giving a complete 3D picture of the surrounding reality.

Note! Binocularity improves visual acuity, providing clear perception visual images.

Three-dimensionality of perception begins to form at the age of two years: the child is able to perceive the world in a three-dimensional image. Immediately after birth, this ability is absent due to inconsistency in the movement of the eyeballs - the eyes “float”. By the age of two months, a baby can already fixate an object with its eyes. At three months, the baby tracks objects in motion located in close proximity to the eyes - hanging bright toys. That is, binocular fixation and fusion reflex are formed.

At six months of age, babies are already able to see objects at different distances. By the age of 12-16 years, the fundus of the eye is completely stabilized, which indicates the completion of the process of formation of binocularity.

Why is binocular vision impaired? For the perfect development of stereoscopic images, certain conditions are necessary:

• absence of strabismus;
• coordinated work of the eye muscles;
• coordinated movements of the eyeballs;
• visual acuity from 0.4;
• equal visual acuity in both eyes;
• proper functioning of the peripheral and central nervous systems;
• absence of pathology in the structure of the lens, retina and cornea.

Ditto for normal operation visual centers require symmetry of the location of the eyeballs, absence of pathology optic nerves, the coincidence of the degree of refraction of the corneas of both eyes and the same vision of both eyes. In the absence of these parameters, binocular vision is impaired. Also, stereoscopic vision is impossible in the absence of one eye.

Note! Stereoscopic vision depends on proper operation visual centers of the brain, which coordinates the fusion reflex of merging two images into one.

Stereoscopic vision impairment

To obtain a clear three-dimensional image, coordinated work of both eyes is required. If the functioning of the eyes is not coordinated, we're talking about about pathology of visual function.

Binocular vision impairment may occur for the following reasons:

• pathology of muscle coordination—motility disorder;
• pathology of the mechanism for synchronizing images into one whole - sensory disorder;
• combination of sensory and motor disorder.

Binocular vision is determined using orthoptic devices. The first test is carried out at three years: children are tested for the functioning of the sensory and motor components of visual function. When strabismus is carried out additional test sensory component of binocular vision. An ophthalmologist specializes in problems of stereoscopic vision.

Important! Timely examination of the child by an ophthalmologist prevents the development of strabismus and serious problems with vision for the future.

What causes a violation of stereoscopic vision? These include:

• inconsistent eye refraction;
• eye muscle defects;
• deformation of the cranial bones;
• pathological processes of orbital tissue;
• brain pathologies;
• toxic poisoning;
• neoplasms in the brain;
• tumors of the visual organs.

The consequence of impaired binocularity is strabismus, the most common pathology of the visual system.

Strabismus

Strabismus is always a lack of binocular vision, since the visual axes of both eyeballs do not converge. There are several forms of pathology:

• valid;
• false;
• hidden.

At false form strabismus, stereoscopic perception of the world is present - this allows us to distinguish it from real strabismus. False strabismus does not require treatment.

Heterophoria (hidden strabismus) is detected by the following method. If a patient covers one eye with a sheet of paper, it will deviate to the side. If the sheet of paper is removed, the eyeball takes the correct position. This feature is not a defect and does not require treatment.

Impaired visual function with strabismus is expressed in the following symptoms:

• bifurcation of the resulting picture of the world;
• frequent dizziness with nausea;
• tilting the head towards the affected eye muscle;
• blocking the mobility of the eye muscle.

The reasons for the development of strabismus are as follows:

• hereditary factor;
• head injury;
• severe infections;
• mental disorder;
• pathologies of the central nervous system.

Strabismus can be corrected, especially in early age. Various methods are used to treat the disease:

• the use of physiotherapy;
• physiotherapy;
• eye lenses and glasses;
• laser correction.

With heterophoria it is possible fast fatiguability eyes, double vision. In this case, prismatic glasses are used for constant wearing. In case of severe heterophoria, it is carried out surgical correction, as with obvious strabismus.

With paralytic strabismus, the cause that caused the visual defect is first removed. Congenital paralytic strabismus in children must be treated as early as possible. Acquired paralytic strabismus is typical for adult patients who have suffered severe infections or illnesses internal organs. Treatment to eliminate the cause of strabismus is usually long-term.

Post-traumatic strabismus is not corrected immediately: 6 months must pass from the moment of injury. In this case, surgical intervention is indicated.

How to diagnose binocular vision

Binocular vision is determined using the following instruments:

• autofluorofractometer;
• ophthalmoscope;
• slit lamp;
• monobinoscope.

How to determine binocular vision yourself? Simple techniques have been developed for this. Let's look at them.

Sokolov's technique

Hold a hollow, binocular-like object, such as rolled-up paper, toward one eye. Focus your gaze through the pipe on one distant object. Now bring it to open eye your palm: it is located near the end of the pipe. If binocularity is not balanced, you will find a hole in your palm through which you can view a distant object.

Kalfa technique

Take a pair of markers/pencils: hold one in a horizontal position, the other in a vertical position. Now try to aim and connect the vertical pencil with the horizontal one. If binocularity is not impaired, you can do this without difficulty, because spatial orientation is well developed.

Reading method

Hold a pen or pencil in front of the tip of your nose (2-3 cm) and try to read the printed text. If you can fully comprehend the text with your vision and read, it means that motor and sensory functions are not impaired. A foreign object (a pen in front of your nose) should not interfere with the perception of the text.

Prevention of binocular defects

Binocular vision in adults can be impaired for several reasons. The correction consists of exercises to strengthen the eye muscles. Wherein, healthy eye closed, and the patient is loaded.

Exercise

This exercise for developing stereoscopic vision can be performed at home. The algorithm of actions is as follows:

1. Attach the visual object to the wall.
2. Move two meters away from the wall.
3. Extend your arm forward with your index finger raised up.
4. Shift your focus to the visual object and look at it through the tip of your finger - the tip of your finger should bifurcate.
5. Shift your focus from your finger to the visual object - now it should split in two.

Target this exercise consists of alternately switching the focus of attention from the finger to the object. An important indicator of the correct development of stereoscopic vision is the clarity of the perceived image. If the image is blurry, this indicates monocular vision.

Important! Any eye exercises should be discussed in advance with an ophthalmologist.

Prevention of visual impairment in children and adults:

• You can’t read books while lying down;
• the workplace should be well lit;
• Take vitamin C regularly to prevent age-related vision loss;
• regularly replenish your body with a complex of essential minerals;
• should be unloaded regularly eye muscles from tension - look into the distance, close and open your eyes, rotate your eyeballs.

You should also be regularly examined by an ophthalmologist and adhere to healthy image life, relieve the eyes and not allow them to get tired, perform eye exercises, treat eye diseases in a timely manner.

Bottom line

Binocular vision is the ability to perceive the picture of the world with both eyes, determine the shape and parameters of objects, navigate in space and determine the location of objects relative to each other. Lack of binocularity is always a decrease in the quality of life due to limited perception of the worldview, as well as a health problem. Strabismus is one of the consequences of impaired binocular vision, which can be congenital or acquired. Modern medicine easy to restore visual functions. The sooner you start vision correction, the more successful the result will be.

You can find many tests on the Internet to check visual acuity or color vision. Just download standard table Sivtseva-Golovin and find out if you have visual impairment. There are online tests to test binocular vision. How do they work and can they replace hardware research methods?

Binocular vision: what is it?

Binocular vision is the ability to see three-dimensionally. Provides this functionality visual analyzer fusion reflex. It works as follows: the brain receives two images from both retinas and combines them into a complete picture. Stereoscopic vision is possible under certain conditions. A person must have good eyesight, eyeballs it must move synchronously, in concert. There are other conditions that ensure stereo vision works. In most cases, they relate to the presence or absence of diseases, ocular and non-ophthalmological. When binocular vision is impaired, a person cannot see normally with both eyes. One partially or completely falls out of the visual process, and without stereo vision it is difficult to navigate in space, since a person cannot determine the distance between visible objects.

Determination of binocular vision online

You can determine whether you have binocular vision yourself at home. This is done using a series of simple experiments or computer programs. An online binocular vision test will give you the opportunity to find out whether or not you have problems with visual functions.

How to pass the binocular vision test?

To do this, you need to upload a picture to the server, for example, an apple. It should be large (about 15 cm in diameter) and located in the center of the monitor. Adjust the brightness of the image. The monitor should not be dim or too bright. You should place it at a distance of 40-45 cm from the monitor. The image is at eye level. Next, you need to extend your finger up and keep it on the same visual axis with the object (apple). Look at the apple. You should be able to see the object between your two fingers. At the same time, your hands and fingers will appear transparent. After this, look at your finger. You will notice that the apple has split in half.

Next step- look at the apple and close your left eye. You should see a finger to the left of the object. When you close your right eye, you will see a finger to the right of the apple.

Evaluation of results

The test is deciphered very simply. If you see all the images described above (a forked apple and a forked finger), then your stereoscopic vision function is working. If there are violations, you will see other images:

• one finger is larger than the second;
• You only ever see one finger;
• fingers disappear and appear, and you cannot focus normally;
• the left finger covers the apple, and the right finger is located very far from it.

What to do if the results are negative?

All these signs indicate that one eye is dominant in you. This is not a reason to panic. You may not be able to pass the online vision test the first time. In addition, there are various exercises to train your vision. However, it is better to consult an ophthalmologist for an examination. The test can only give a rough idea of ​​how spatial vision works. In the presence of pathologies, for example, with strabismus, an examination for special devices. One such device is a sign projector.

Wars test. Checking on the sign projector

A sign projector is a device used by ophthalmologists to determine the degree of visual impairment. A projector shows signs on the wall, and a person looks at them through green and red lenses. There are only 5 signs: two green, two red and white. In the presence of binocular vision, the subject sees four figures, if the vision is simultaneous (that is, one and then the second eye works alternately) - 5 figures, and with monocular vision (one eye works) - the patient distinguishes either two red or three green figures.

Advantages of the technique

The sign projector experiment is also called the four-point experiment. It is the most common in ophthalmology, as it allows you to accurately determine the nature of vision. The results of the study can only be deciphered by a doctor. The advantage of this technique is its accuracy. However, it is not suitable for testing vision in very young patients who cannot tell themselves what they see. They are examined using other instruments.

Binocular disturbances can lead to various diseases. In most cases, the prognosis for treatment is favorable. It is important to start treating any disease on time and systematically