Why double vision and what to do?

Both eyes are involved in obtaining a three-dimensional image of objects around us. The central section of the visual analyzer of the brain receives a signal from each of them at the same time, which, superimposed on each other, merge into a single stereoscopic image. We are used to seeing a single picture and if it suddenly begins to double, this deprives us of confidence in orientation in space, tires the brain and disrupts coordination of movements. Double vision or diplopia leads to overstrain of the visual organs and can cause serious discomfort - dizziness, nausea, heaviness and pain in the eyes and head. The appearance of such a symptom is difficult to ignore, it causes very great inconvenience, since we use our eyes constantly. Even if double vision appears occasionally and when looking in a certain direction, this requires diagnostics, since it can indicate the development of a serious pathological process in the body.

Why do I see double?

Obtaining a clear visual image depends on the coordinated work of several structural elements of the visual system:

• the cornea and lens, which perform the optical functions of conducting, refraction and focusing light rays;
• muscles that provide fusional movements of the eye;
• optic nerves that transmit information to the visual analyzer of the brain.

A problem with any of these elements can lead to a discrepancy in the location of the light beam from the object on the retina of one eye and the other, a violation of the symmetry of the alignment of the visual fields, and no merging or fusion of images from the retinas of both eyes into one - binocular diplopia occurs. It is mainly caused by paralysis (paresis) of the external eye muscles. This type of double vision is much more common than monocular diplopia, when the display of a visual object occurs in two places on the retina of one eye (dispersion of light rays). Double vision does not disappear when looking at an object with one damaged eye. Monocular diplopia is caused not by neurological, but by functional damage to the cornea and lens, inflammatory, dystrophic, traumatic (keratitis, iridocyclitis, keratoconus, cataract, astigmatism, lens dislocation), hemorrhage into the vitreous body. Temporary monocular diplopia may occur when the cornea is not sufficiently hydrated.

Binocular diplopia is a condition when double vision occurs with both eyes open. If one (either) eye is closed, the image stops doubling. The cause of double vision is the deviation of the visual axis in one eye. Double vision of the visible object occurs due to a violation of the motor skills of one eye, due to which coordinated movements of the eyeballs become impossible. Motor dysfunction can be caused by exhaustion of the oculomotor muscles, disruption of their innervation, traumatic lesions of the orbit, massive hemorrhages.

According to the mechanism of development, a distinction is made between motor, formed against the background of normally preserved binocular vision as a result of complete or partial loss of the ability to contract the external eye muscles, and sensory, developed with preserved eye mobility as a result of dysfunction of merging monocular images into a single image, which often occurs after the restoration of symmetry in a patient with strabismus. When it is impossible to distinguish the motor genesis of double vision from the sensory one, mixed diplopia is distinguished.

The causes of motor diplopia are complete (paralysis) or partial (paresis) inability to contract the muscles involved in eyeball movements, nuclear palsies as a result of head injuries, neurosurgical interventions, cerebral vascular diseases and infections affecting the brainstem (tetanus, diphtheria, rubella, mumps). Usually, the function of the abducens nerve is completely impaired. A few fewer cases are associated with dysfunction of the oculomotor nerve, as a rule, its lesions are partial. Dysfunction of the trochlear nerve is an even rarer phenomenon.

In the central part of the visual field, double vision does not occur; the image begins to double when the gaze is raised, lowered, or transferred to the tip of the nose, which depends on the damage to the corresponding muscle - rectus: upper, lower, and inner.

The least common cause of double vision is damage to the trochlear nerve. It is always partial, when the patient raises his eyes or looks toward the healthy eye.

The main diffuse lesion of the neuromuscular system, leading to double vision, is myasthenia. Much less often, such symptoms are manifested by myopathy, progressive supranuclear gaze palsy, multiple sclerosis.

Thyroid dysfunction (hyperthyroidism, thyrotoxicosis) can lead to peripheral damage to the extraocular muscles (thyrogenic myopathy), accompanied by double vision, and also - with an aneurysm of the carotid artery, compression of the oculomotor nerve occurs.

This type of visual pathology occurs with traumatic injuries to the eye orbit, if there is direct damage to muscle tissue, all oculomotor nerves, or displacement of the eyeball as a result of a fracture of the lower orbital wall.

Double vision may occur as a consequence of surgical intervention to eliminate retinal detachment or to strengthen the sclera of the eyeball in case of progressive myopia.

Intracerebral neoplasms, diabetes mellitus, and tuberculous meningitis are risk factors for the development of diplopia.

Congenital defects of image fusion can also cause it.

What disease causes double vision and why?

Complaints of double vision occur in patients with various pathological conditions, some of which at first glance are not related to vision function.

Double vision in cervical osteochondrosis occurs due to a disorder in the vessels supplying the brain. The consequence is hypoxia and insufficient nutrition of the muscle tissue and nerve fibers of the eyes and the visual center. Over time, dystrophic changes in the structures of the eye appear, the mobility of the eyeballs is limited, the coordinated work of the organs of vision is disrupted, which leads to the impossibility of fusion. The visual image can double in different planes. In most cases, binocular diplopia develops as a result of convergent concomitant strabismus acquired at a respectable age. Complaints of double vision in osteochondrosis may indicate the development of accommodation disorders, muscle atrophy and / or clouding of the lens, the initial stage of glaucoma.

Impaired innervation of the eye muscles is one of the symptoms of a stroke. Ischemic processes in the brainstem, cerebellum, vertebral-basilar basin of the brain can be accompanied by motor dysfunction of the eyeballs. Double vision in stroke is more pronounced on the side of the affected muscle.

Hypertension may be accompanied by double vision. Many complain of symptoms such as high blood pressure and double vision. Diplopia usually occurs with sharp jumps in blood pressure, in such cases there is also nausea and headache, impaired coordination of movements, weakness, increased heart rate. These symptoms require examination, as they indicate vascular pathologies and circulatory disorders. They can be harbingers of a stroke.

Complaints of double vision are common with VSD (vegetative-vascular dystonia), which disrupts the body's control over vascular tone. A malfunction of the autonomic nervous system can be caused by a whole bunch of diseases, and it is advisable to establish the cause of these symptoms. VSD is a symptom complex, not a diagnosis, and you should not brush it aside, the consequences can be severe.

Diplopia is one of the initial symptoms of a severe and currently incurable disease – multiple sclerosis. This is an autoimmune process of destruction of the myelin sheath that protects nerve fibers, which leads to a partial or complete interruption of the transmission of nerve impulses and simultaneous damage to several parts of the nervous system.

Astigmatism is a fairly common cause of diplopia. With this pathology, as a rule (more than 98%), the cornea is affected, it has an irregular shape, sometimes - the lens of the eye. A defect appears in the optical system of the organ of vision, as a result of which several images are reflected on the retina of the diseased eye (monocular diplopia). Astigmatism can be congenital and acquired. It must be corrected.

Double vision is quite possible with diabetes. In this case, small blood vessels are affected, including those that supply blood to the retina, and the oculomotor nerves are also affected. Most long-term diabetics develop vision pathologies. The cause of double vision with diabetes can be hemorrhage in the vitreous body, cataracts, glaucoma.

Closed TBI (4/5 cases of head contusion) leads to vision impairment. The causes of this are ruptured blood vessels in the brain, nerve damage, cerebral edema, ischemic processes, microtraumas of the skull base, leading to hypoxia, compression of the optic nerve, and transformations of the fundus. Double vision is one of the signs of a severe concussion. With a minor concussion, vision can stabilize on its own, however, periodic double vision can be observed even after a significant period after a head contusion.

Double vision may indicate the formation of a carotid artery aneurysm, tumor, or hematoma.

Diplopia can be permanent or occur periodically. For example, double vision may occur after sleep, or after physical or visual stress. If this is a one-time situation, then there is nothing to worry about, but if in some situation the image is constantly doubled, then you need to see a doctor, as this may be a sign of a developing pathology.

Basically, diplopia after surgery is temporary. Double vision after laser vision correction (myopia correction), especially in advanced cases, is a predictable condition. It occurs due to postoperative disorders of binocular localization of visual images ("fear of fusion"). Vision usually stabilizes after surgery within about a month, some patients need a longer period.

If the visual image doubles after cataract surgery, this may be a sign of intraocular lens displacement. In such cases, you need to see a doctor as soon as possible. Time is important for correcting this complication. If you seek help late, for example, after three months, the correction becomes more complicated. In general, you need to see a doctor as soon as possible about any postoperative complications. Perhaps nothing terrible has happened, and you just need to wait. Or you may need a corrective procedure, and the sooner you do it, before the lens has time to heal, the easier the recovery process will be.

When the image doubles after a blow to the eye, this may indicate traumatic damage to the cornea, muscles or nerves, a fracture of the lower orbital wall. After an eye injury, it is imperative to see an ophthalmologist.

Diplopia can be temporary and occur as a consequence of taking certain drugs that affect the brain, such as anticonvulsants, barbiturates, and anesthetics. Double vision occurs after anesthesia, as it affects blood circulation and metabolic processes in the brain.

People who spend a lot of time in front of a monitor experience eye strain and double vision from the computer. This is typical for dry eye syndrome. To prevent unpleasant symptoms, you need to follow the rules for working at the computer.

Temporary diplopia can be caused by alcohol, food or drug intoxication, observed in severe infectious diseases, and in case of an overdose of Botox (anti-wrinkle injections).

When you regularly see double in the dark, you need to get examined. This condition can be caused by a deficiency of vitamin A. Its leading symptom is the so-called "night blindness" - poor vision in the dark and is accompanied by dry eyes and inflammation.

If you see double while walking, you also need to get examined. At first, many symptoms appear during physical activity and disappear at rest. Walking is not such a big load and if you see double while moving, this is a serious warning sign.

Neurogenic diplopia is a functional visual impairment and, according to experts, is the most difficult to explain variant of pathology. It occurs in meningoencephalitis, endocrine diseases, hysterical disorders, asthenopia.

There are many risk factors for diplopia, some of which require immediate treatment, so if double vision occurs periodically, you should see a doctor, because inactivity may result in an advanced disease.

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Pathogenesis

The basis of the mechanism for the development of monocular diplopia is the dispersion of light rays due to congenital or acquired defects of the cornea and lens, as a result of which several images of a visual object appear on the retina of one eye.

The pathogenesis of binocular double vision of the motor type is acquired due to various reasons already mentioned paralytic strabismus. In this case, the light beam enters the foveal zone of the healthy eye and the peripheral part of the retina of the eye with limited mobility. The ability to see normally with both eyes is usually not impaired with motor diplopia. With paresis (paralysis) of the muscles, binocular fusion of images can be achieved by compensating for the actions of the paralyzed muscle by turning the head in its direction, as a result of which the image in the squinting eye enters the central pit of the retina (fovea).

The mechanism of development of binocular sensory diplopia is the impossibility of fusion of two images, given that the light rays enter the fovea of the retinas of both eyes. The arrangement of images is symmetrical in all parts of the visual field, eye mobility is preserved, but fusion does not occur due to congenital or later insufficiency of the apparatus merging images (fusion), narrowing of the fusion amplitude. Sensory double vision can manifest itself during the formation of strabismus, when the symmetry of the arrangement of the eyes is just beginning to be violated, and the light flux from the visual image enters the affected eye not in the fovea, but nearby, and the images do not merge. Provided that strabismus develops in childhood, the mechanism suppressing the image that does not enter the central fovea is triggered, and double vision is not observed. In adults, the suppression mechanism is weakened, therefore, with the development of strabismus, the dispersion of light rays is more pronounced and persists for a longer time.

In the pathogenesis of mixed diplopia, both factors are at work: functional difficulty with fusion and muscle insufficiency.

Depending on which muscles or nerves are affected, the image may appear double both vertically and horizontally.

Vertical double vision occurs when the oblique muscles, oculomotor or trochlear nerve are affected.

Horizontal double vision occurs with weakness of the lateral or medial rectus muscle and occurs with damage to the oculomotor or abducens nerve, as well as internuclear ophthalmoplegia.

Statistics

According to various studies, the ideal balance of muscles that ensure the correct position of the eyes is observed quite rarely, only in 20-30% of the population. In the rest, the visual axis of one eye deviates periodically to one side or the other. This is the so-called latent strabismus. It can be assumed that even under completely innocent adverse conditions (eye strain, severe fatigue, taking medications, incorrectly selected glasses, etc.), the majority of the population may experience temporary double vision.

Among people who sought help for double vision, 75% had binocular diplopia, while the rest had monocular diplopia. The first type of double vision is considered a more alarming sign, since it is caused by a violation of the innervation of the periorbital muscles or its weakness, which may indicate the presence of neuromuscular pathologies and systemic diseases that cause them.

Symptoms

The first signs of diplopia, as a rule, are noticed by people immediately. They cause great discomfort. They manifest themselves in different ways. Some patients complain of sudden and constant double vision, while others have double vision from time to time or in a certain direction of gaze, when turning and tilting the head.

The pictures also differ – they are layered, placed next to each other or one below the other.

Diplopia is almost always accompanied by other symptoms. When a person sees double and feels dizzy, nausea rises in the throat, such signs may indicate a jump in blood pressure, concussion and spinal injury. Such symptoms, appearing from time to time, may indicate the presence of vegetative-vascular dystonia, osteochondrosis of the cervical spine, chronic ischemia of cerebral vessels, diseases of the heart muscle and anemia, various toxic effects. The appearance of such signs may precede a stroke or heart attack.

If the above symptoms are accompanied by pain or noise in the ears, hearing loss and discharge from the ear canal, then this condition may be observed with otitis media. If hearing loss progresses, the patient is weak and vomits, then it is Meniere's disease.

Dizziness, nausea and diplopia can be present in the symptom complex of approximately 80 different diseases, therefore, to establish the cause of such symptoms, you need to visit a doctor without delay.

It happens that objects located at a close distance are clearly visible, but double vision occurs in the distance. The most probable cause of such symptoms is a violation of the ability of the optical system of the eye to provide a high-quality image of objects located at different distances (i.e. accommodation). Such disorders affect people who spend a lot of time at the computer, forced to focus their gaze for a long time on small icons or objects located close by. A blurry double image of objects located at a distance often signals developing myopia.

Double vision and headache also require a specialist consultation. Similar ailments are observed during a migraine attack, vegetative-vascular dystonia, neurosis, hypertension. Sharp pain that occurs simultaneously with double vision is observed during cerebral vascular spasm, transient ischemic attacks, stroke, as well as flu, encephalitis and meningitis. Periodic pain and double vision may follow a head injury, be symptoms of a developing brain tumor or carotid artery aneurysm. These are alarming symptoms that are possible with many pathologies and require examination.

When the image is double in one eye, monocular diplopia is diagnosed. To verify this, you need to look with each eye in turn, closing the adjacent one. In this way, you can detect double vision in the left, right eye, or both at once, simply by looking with the eyes separately, not simultaneously, and seeing a double image. This symptom most likely indicates corneal pathologies that have appeared due to various reasons - inflammation, trauma, surgery, or at least its dryness. Problems with the lens of the eye - dislocation, dislocation, clouding, development of cataracts. In the latter case, double vision is observed when reading. Congenital anomalies - columba, polycoria, acquired - pterygium, chalazion, dermoid cyst, trauma can lead to double vision in one eye.

When a person complains that his eye hurts and the image of a visual object doubles, he may have: iridocyclitis, glaucoma, inflammation of the optic nerve, cornea, conjunctiva, skin of the eyelids. Getting a foreign body into the eye, xerophthalmia and migraine can be accompanied by the same symptoms. Pain and double vision in the eye after an injury are a reason for an urgent examination.

Complaints about weakness, accompanied by double vision, are certainly better voiced in the doctor's office. It is more likely that these symptoms are caused by general diseases: osteochondrosis, vegetative-vascular dystonia, endocrine pathologies, multiple sclerosis, infectious diseases. Weakness and diplopia may indicate hypertension and vascular catastrophe, heart damage and intoxication. After a head injury, the victim may also be bothered by double vision and weakness.

Sometimes the complaint sounds like this: "I see well with each eye, but double with both." These are symptoms of binocular diplopia. The object of vision doubles only when a person looks with both eyes at the same time. As soon as one of them is closed, the double vision stops. Most diplopia of this type is caused by muscle paralysis and is considered an alarming symptom of serious disorders.

Judging by the number of questions about double vision during pregnancy, this condition is not uncommon. It is most likely associated with overstrain of the extraocular muscles, xerophthalmia. If a woman has not recently injured her eyes and head, she can do exercises that provide relaxation of the periorbital muscles, reduce visual strain. But it is necessary to remember that there are many pathologies, one of the signs of which is diplopia. Therefore, if eye exercises are ineffective, you should consult a doctor about this problem.

Any pathological causes can cause double vision in a child. But pediatric ophthalmologists often encounter physiological diplopia, when objects visible with peripheral vision, but not those in the line of sight, are doubled.

In addition, diplopia often occurs during the functional treatment of strabismus in pediatric practice. Moreover, in a child (unlike an adult), the appearance of diplopia is considered a favorable prognosis, indicating the possibility of restoring normal vision.

Other accompanying symptoms can help to suggest what is causing diplopia.

Double vision and so-called floaters in the eyes appear in nearsighted people when looking into the distance and are a symptom of destructive changes in the vitreous body.

In addition, flashing spots often accompany migraines, sudden pressure changes, spasms of the eye and cerebral vessels, thus multiple sclerosis, infectious and inflammatory diseases and other diseases leading to vascular spasms, muscle innervation disorders and fluctuations in blood pressure can manifest in this way.

Redness of the eyes and double vision in front of them are typical for inflammatory processes of the eyelids and structural elements of the eye of various origins - infectious, allergic, traumatic, general infectious diseases (ARI, flu), computer vision syndrome and other increased stress on the organs of vision and the body in general.

Periodically occurring darkening of the eyes, accompanying diplopia, may indicate the presence of anemia, hypotension, migraine, vegetative-vascular dystonia, cervical osteochondrosis. With sclerotic changes in the cerebral vessels, attacks occur during which it darkens in the eyes.

The symptom complex of glaucoma includes diplopia, blurred vision, veil and flies, which can also be interpreted as "it gets dark in the eyes". In addition, pain in the eyes and their hyperemia, narrowing of the angle of vision, a significant decrease in the quality of vision in the dark are often disturbing.

Sand in the eyes and double vision occur most often with dry eye syndrome. When a foreign body gets in, such symptoms are usually felt in one eye.

The feeling that sand has got into the eyes occurs with many eye diseases, with general diseases that cause dilation and inflammation of the blood vessels in the eyes. Only a specialist can diagnose the disease, so if such symptoms occur frequently or bother you constantly, you must consult a doctor without delay.

Double vision rarely occurs without accompanying symptoms. It is accompanied by dizziness and nausea, impaired coordination, headache, and discomfort in the eyes. Diplopia causes a lot of inconvenience to the patient, affecting all areas of life. Double vision can be observed in all directions of vision (complete) or in one (partial). The image can double at different distances, close or far, or at any distance. One of the images can be clearer and brighter than the other, they can overlap or be close. There are many options. The patient, as doctors note, can always say exactly at what moment the double vision began, even if the appearance of the symptom is not associated with an injury.

Diagnostics

When a patient consults a doctor complaining of double vision, the interview and examination establish the type of double vision and the events preceding it - injuries, diseases, infections. The condition of the conjunctiva and the eyeball itself of both eyes, the reactions of the pupils to light and their symmetry are visually assessed, the fundus, its vessels, retina and optic disc are examined with an ophthalmoscope, standard ophthalmological diagnostics are performed (checking visual acuity, color perception and refraction with the help of autorefkeratometer, phoroptor devices). Latent strabismus is diagnosed by means of coordinatemetry and provoking double vision. If the patient wears glasses or contact lenses, their effect on the quality of vision is taken into account.

During the examination, the position of the eyelids and eyeballs, their symmetry and mobility in all directions (up and down, right and left, diagonally) are assessed. If no visual disturbances are detected, various tests are performed depending on the technical equipment of the institution: "cover test" (eye test with covering), color test with the head in a straight and turned position, Haab tests and other tests are performed depending on the suspected lesion. The main goal of diagnostics is to determine the nature and organ of the lesion that caused diplopia. Modern computerized instrumental diagnostics are often used, allowing a diagnosis to be made fairly quickly. In ophthalmology, computer accommodation, ultrasound examination of the eyeball and computer coherence tomography are used, allowing almost all structures of the eye to be examined.

Laboratory tests are carried out - in case of inflammatory processes, a clinical blood test, bacterioscopic examination of a smear from the conjunctiva, tear fluid, an allergy test may be prescribed; if diabetes mellitus is suspected, the concentration of glucose in the blood is checked; hyperthyroidism - tests for thyroid hormones, other necessary procedures at the discretion of the doctor.

The patient may need an advisory opinion from doctors of other specialties: a neurologist, endocrinologist, oncologist, psychiatrist, additional studies of brain structures - tomography, ultrasound.

After examination and diagnostic studies, differential diagnostics are performed based on their data. Organic eye pathologies are excluded or confirmed: myopia, strabismus, congenital defects of the cornea and lens, columba (when the pupil "goes" onto part of the missing iris), dystrophic anomalies of the cornea (bulging, flattening, clouding) and retina, acquired - dystrophy of the retina, cornea, lens, macular degeneration (ischemic processes in the retina caused by vascular insufficiency), inflammatory eye diseases, in particular, keratitis (inflammation of the cornea), lens dislocation, glaucoma, traumatic organic lesions, postoperative complications - scars, "fear of fusion" and others.

If organic pathologies are excluded, then dry eye syndrome or damage to the eye muscles and/or nerves caused by general diseases – hypertension, diabetes, multiple sclerosis, cerebral artery aneurysm, thyrotoxicosis – are often diagnosed, which are confirmed by appropriate studies.

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Consequences and complications

It is not recommended to ignore the appearance of such a symptom as double vision, since in addition to visual fatigue and dry eyes, it can be a sign of the development of serious diseases, even incurable ones such as glaucoma or multiple sclerosis, however, early diagnosis of which and timely initiation of supportive therapy allows the patient to lead a practically full life.

Diplopia causes great inconvenience to people not only at work, but also in everyday life, up to the loss of ability to work and habitual daily skills. Often, patients squint one eye or wear an eye patch to eliminate discomfort.

And if double vision is part of a complex of symptoms of serious diseases (glaucoma, hypertension, neoplasms) or is a precursor to a stroke, then the lack of timely diagnosis and treatment can result in loss of vision, disability and even death of the patient.

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Prevention

Exercises for training the eye muscles have a good effect in preventing loss of visual acuity and the development of eye diseases. By observing occupational hygiene and giving the eyes a rest, we already reduce the likelihood of visual disorders by several times.

An active lifestyle, no bad habits, walks in the fresh air, proper nutrition - eating a variety of foods, including those rich in vitamins A, E, C, minerals, lutein, will allow us not only to preserve our vision, but also, in general, to remain healthier - not to suffer from hypertension, nervous and endocrine diseases, hysterical psychoses.

And if diseases do exist, as well as in the case of injuries, consult a doctor, establish a diagnosis in a timely manner, preventing the development of complications.

Forecast

The absence of treatment for binocular pathology mainly leads to the patient adapting to choose the main image and abstracting from the other. Adaptation occurs more quickly in patients with a large angle of strabismus: the further the images are from each other, the easier it is for the patient to adapt and compensate for double vision, for example, by turning the head. However, independent rehabilitation drags on for years. Modern ophthalmology has a variety of methods aimed at restoring fusion ability and normalizing vision.

In case of monocular diplopia, it is necessary to undergo treatment, since this form of the disease is often caused by serious visual pathologies that can lead to complete blindness.

However, timely visit to a doctor, diagnosis and treatment allows, in general, to get rid of this painful visual defect.

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