What does it mean if one pupil is larger than the other? Reasons why one pupil is larger than the other

Pupils of different sizes, or scientifically anisocoria, are an anomaly in which one pupil is larger than the other, the cause of the phenomenon does not mean a serious disease. With anisocoria, not only the size of the pupils varies, but also the reaction to sunlight. In one pupil it may be weak or absent at all.

It seems that dilated and, moreover, unequal size pupils are a reason to immediately consult a doctor, but according to medical standards, the normal range of difference is up to a millimeter. If some other point does not bother you, there are no other symptoms of serious pathology, then there is nothing to worry about. However, in an adult, under certain circumstances, pupils of different sizes are signs of problems with the functioning of the brain; these may be disorders of the nervous and visceral type. Eye diseases also cannot be ruled out.

General information

Questions about different diameter pupillary problems in one eye occur frequently, especially among parents of infants. Sometimes children have not just a noticeable difference, but serious dimensional differences; there are different pigmentation options. However, in most cases, very few of these symptoms are a sure sign of pathology.

You can meet a person whose one pupil is dilated. At the same time, he has no diseases, he leads healthy image life, does not suffer from nervous and professional shocks. According to data, 18-22 percent of people have a larger pupil in one eye. At the same time, different pupil sizes do not interfere with their lives, but are considered a physiological condition, in many cases of a congenital nature.

However, it is important to understand that sometimes pupils of different sizes indicate the presence of a certain disease in the body, while the process progresses, causing certain risks. In medicine, the pupil refers to the central opening in the iris of the eye. Light rays are collected in the pupil, and the retina perceives them. There are muscles around, through which the eye controls the amount of light rays on the retina.

If you move into a room with insufficient lighting, the pupil will dilate to capture more light. In a room with sufficient illumination, the pupil does not expand, but narrows, so as not to “burn out” the retina. For humans, this mechanism of adaptation is very important, since the ability to adapt to different lighting conditions helps in collecting more information about the objects and phenomena that surround a person.

A dilated pupil appears not only with a lack of light, but also with uneven lighting. In this case, you may notice that the right pupil is larger than the left or the opposite situation is present. However, if the difference does not exceed a millimeter, there is no cause for concern.

Causes of the condition

There is no clear answer to the question why one pupil is larger than the other. There are problems with diagnosing diseases, since most people do not pay attention to this problem, believing that it is:

• heredity;
• racial characteristics;
• a unique individual feature.

However, this is not a completely correct approach. It was stated above that the right pupil is larger than the left - this does not indicate pathology, but many forget that a difference of more than a millimeter is a reason to see a doctor. There may be a high risk of side effects with simultaneous deterioration in vision, which you began to notice, how one of the pupils could not dilate to the same size as your neighbor.

For many, one pupil is wider than the other due to injury or microtrauma of the eyeball, or individual muscle groups. A pupil that is wide relative to the second one may appear when the nerve responsible for eye movement is damaged. Impaired blood circulation in the brain, malignant tumors, damage to brain tissue, and an aneurysm cannot be ruled out. Differences in pupils can be caused by herpes, Eydie's syndrome, tonic pupil syndrome and heredity.

If it’s been six months since you noticed differences in pupil size, but at the same time further development does not occur, most likely, you will not face serious complications. The cause of such changes may be an inflammatory process - problems with the lymph nodes. After eliminating such pathologies, the pupil becomes smaller and the indicators level out, so you cannot self-medicate. The cause of the problem must be identified by the attending physician, who knows how to treat a particular disease, which as a result of therapy will develop more slowly or go away altogether.

The causes of anisocoria in adults and children are similar. At any age, the reason for the difference in pupil size is ordinary myopia, which develops differently, and in the eye with more pathology, the pupil will be wider.

If an adult experiences permanent dilation of the pupil for more than a month, with little reaction to a light source, there is a chance that it is Holm-Eydie syndrome. The cause of this pathology is excessive sensitivity to pilocarpine.

Anisocoria is caused by compression of the nerve responsible for eye movement. In this case, the pupil is wide in size, but reacts poorly or does not change at all when exposed to light. Do not forget about the banal use medicines, which seriously affect pupil dilation. Such by-effect persecutes asthmatics.

Examination and treatment

To make a correct diagnosis, an examination by an ophthalmologist will be required. He interviews the patient, examines and checks visual acuity. Suitable therapy is selected only after the diagnosis has been clarified. Sometimes one inspection is not enough to collect all the information. Then the patient is prescribed additional examinations and tests.

During the examination, doctors highlight a number of points that require attention. This is the dynamics with which the contraction occurs, how symmetrically this process is carried out, determines the size in conditions of low and strong lighting.

If there are pupils that differ in size, the one that cannot respond correctly to the light source will be considered pathological. In the dark, expansion occurs, and with sufficient lighting, a wide object is considered anomalous.

Additionally, in some pathologies the patient complains of pain, double vision and ptosis. It is important for the doctor to know this in order to make the correct diagnosis. Horner's syndrome can be determined using a pharmacological test. To check the head, an MRI or MSCT is prescribed.

If the cause of the disease is heredity, then treatment is not required. If the patient is concerned about this from an aesthetic point of view, ophthalmologists offer ophthalmic surgery. This can be corrected with eye drops, but constant use is dangerous due to side effects.

Treatment is not required even in the absence of pathology, after diagnosis. In this case, this is considered an individual characteristic of the patient. In other cases, the basis of treatment is getting rid of the pathology that caused the malfunction. This may be the use of antibacterial and anti-inflammatory drugs. Corticosteroids are sometimes required.

Normally, the pupils have the same diameter and react to light synchronously, i.e. friendly. However, it happens that in a child or an adult one pupil is dilated more than the other, and this fact worries a person for good reason. Their unequal size is called anisocoria in medicine, which is a symptom of many disorders. nervous system, as well as damage to the eye itself.

Causes

Why is one pupil larger than the other? Its diameter is controlled by the centers of the oculomotor nerve - the third pair of cranial nerves. Their nuclei are located in the brain, and their work is normally coordinated. However, sometimes mismatch occurs due to various factors.

There may be several reasons why one pupil is larger than the other:

1. Migraine or...
2. Nervous system infections, eclampsia.
3. Multiple sclerosis of one of a pair of oculomotor nerves.
4. Congenital pathology.
5. Traumatic eye injury, inflammation. Inflammatory diseases (iridocyclitis) are the cause of unilateral mydriasis or miosis. Eye injuries lead to damage to the pupillary muscles. As a result, its diameter is not adjusted properly.
6. Reflex when the lungs are damaged by tuberculosis. When tuberculosis affects the apex of the lung on the affected side, mydriasis of the eye occurs - Roque's symptom.
7. as a result of strokes and traumatic brain injuries.
8. Use narcotic substances.
9. Tumors of the central nervous system.
10. Neck injuries.
11. Endocrine pathology, thyroid carcinoma.
12. Eydie syndrome with congenital myotonia, ocular herpes. Herpes zoster and ocular herpes viruses can infect both the pupil itself and the nerves that go to it. As a result, unilateral mydriasis or miosis occurs.

Migraine

Migraine or cluster pain – common reason anisocoria. With a migraine, blood circulation is disrupted in one of the hemispheres of the central nervous system. Therefore, its old name is hemicrania. With cluster pain, blood vessels also dilate, swelling of the brain tissue increases, and intracranial pressure increases. Cluster pain and migraine are characterized by Horner's syndrome, which includes miosis of the eye on the affected side, redness of the eyelid and conjunctiva, retraction of the eye, drooping of the eyelid.

Neuroinfections

Infections of the nervous system, such as meningitis, lead to disruption of the nuclei of the oculomotor nerves. In parallel with anisocoria, patients experience weakening or strengthening of reflexes, headaches, and neck stiffness. Patients cannot pull their chin to their neck. Other neurological reflexes are also possible.

Multiple sclerosis

The oculomotor nerve can be affected by an autoimmune nerve disease called multiple sclerosis, which is characterized by the formation of scar tissue in the nerve fibers. Electrical impulse almost stops passing through such nerves. Therefore, the autonomic fibers, as well as the sensory fibers going to the eye, stop working as they should. As a result, the pupils do not respond properly to changes in light.

Hemorrhage

Post-traumatic hematomas can compress important brain structures, such as the brainstem. This leads to herniation and anisocoria. In strokes caused by thrombosis of the arteries supplying the brain or rupture of a vessel, mydriasis or miosis of the eye, and anisocoria may also occur.

Brain tumors and abscesses

Brain tumors, growing, cause edematous processes. Sometimes wedging of the trunk occurs with large tumors. Hemorrhages are also possible when they grow into blood vessels or compress surrounding tissues.

Alcohol or drug intoxication

Usually, with alcohol abuse and taking drugs: cocaine, marijuana, cannabis, both pupils dilate (mydriasis). However, there is also uneven expansion.

Mydriasis is also possible in case of poisoning with belladonna alkaloids - atropine, hyoscine, scopolamine. Constriction of the pupil (miosis) can be caused by organophosphorus compounds and acetylcholinesterase inhibitors: Proserin, Kalimin.

Typically, poisoning is caused by simultaneous mydriasis or miosis. However, if one of the eyes or nerves or centers in the brain is damaged, one of the pupils may not respond to the action of the chemical substance.

Symptoms of diseases with uneven pupil dilation

In addition to mydriasis or miosis, in diseases leading to anisocoria, other signs of disorders are possible. Anisocoria is usually accompanied by the following symptoms:

1. Torticollis.
2. The child has heterochromia, i.e. different colour eye.
3. Visual impairment.
4. Increased photosensitivity up to photophobia.
5. With migraines, increased sensitivity to smells and sounds.
6. Pain in the eyes.

Diagnostics

If there is mydriasis or miosis of the eye, then it is necessary to visit a neurologist or ophthalmologist. Examinations that need to be completed:

1. Ultrasound of the brain.
2. Electroencephalography.
3. Cocaine test.

It is important to learn: problems of the peripheral nervous system and retina.

? Diagnosis and treatment of pathology.

All about: classification, causes, treatment, elimination of the causes of pathology.

Treatment

In case of poisoning, resuscitation measures are necessary: ​​gastric lavage, use of enterosorbents (Smecta, activated carbon).

If anisocoria is caused by a traumatic injury to the nervous system, it is necessary to remove the hematoma that has pressed the brainstem. The operation is performed with craniotomy.

Treatment of multiple sclerosis is carried out using immunosuppressants, glucocorticoids, and donor immunoglobulins to suppress inflammation.

For herpes infection, Acyclovir and interferons are used.

Conclusion

If one pupil is wider than the other, this is a cause for concern and see a doctor. This often means a serious pathology, potentially life-threatening. Anisocoria due to head trauma is fatal dangerous symptom, indicates that the trunk is wedged.

One pupil becomes larger than the other if there are pathologies in the body.

The pupil is a round hole in the center of the iris of the eye that periodically changes size to change the flow of light entering the retina.

The pupil is driven by the muscular system.

The condition characterized by asymmetry of the right and left pupils is called anisocoria in the scientific world. The manifestations of this pathology are determined independently: it is enough to see two pupils with unequal sizes. This indicates an acquired disease or birth defect. Deviations in pupil size are successfully diagnosed and treatable.

Pupil asymmetry is often observed in healthy people, even if their lifestyle is correct. 20 percent of the world's population has different pupils.

This does not affect Everyday life. Sometimes this condition indicates a serious health problem.

It is important to establish which of the pupils is deviated from the norm. This will help to correctly determine the cause of the disorder and prescribe quality treatment. When diagnosing, it is necessary to exclude the use of narcotic drugs that cause such disorders.

Doctors define three groups of the described pathology in accordance with:

1. Congenital or acquired disorder resulting from eye damage.
2. Unilateral or bilateral anisocoria.
3. The etiology of the disease is ocular or general.

Reasons for different pupil sizes in adults

Often the reasons why the pupils of an adult and a child have different sizes are the same. At any age it is caused by myopia. The pupil of the eye that sees worse dilates more. This is a sign of pathology.

If the period during which pupil dilation is determined has exceeded the four-week mark, and a weakened reaction to a light stimulus and slow dilation have been noted, then it is possible we're talking about about the manifestation of Eydie syndrome.

This condition is characterized by disturbances in the innervation of the muscles of the pupil and, as a result, pupils of different sizes. Detection often occurs randomly due to lack of discomfort.

In some cases, anisocoria occurs as a result of severe compression of the eyeball, affecting the oculomotor nerve. Associated symptoms are diplopia and paresis.

TO mechanical damage It is customary to attribute damage to the nerves surrounding the eyeball. The cause is an unsuccessful ophthalmological procedure or a penetrating wound in the eye area.

If the reason for the change in the size of only one pupil in an adult is not injury or external damage, then we can talk about medicinal mydriasis. The pupil reacts poorly to light and does not contract when using pilocarpine.

In general, the causes of this condition are varied.

They are divided into two groups:

1. Ophthalmological.
2. Neurological.

A change in the pupil that occurs due to eye diseases has one of the following reasons:

1. Uveitis.
2. Iritis.
3. Iridocyclitis.
4. Operations and injuries on the eyes.
5. Implanted lens.

If we talk about the causes of anisocoria being neurological diseases, then the following should be mentioned:

1. Horner's syndrome: can develop with concomitant diseases of the neck, head, and lungs.
2. Eydie syndrome: the causes of this disease are still unclear.
3. Damage to the nerve fibers of the eyeball.
4. Nerve palsy; often a consequence of a stroke or brain tumors.
5. Herpes zoster.
6. The use of certain drugs, including narcotic drugs.

• decreased visual acuity;
• bifurcation;
• loss of vision;
• headache;
• feeling of fog in the visibility zone;
• temperature;
• nausea;
• eye pain;
• fear of light.

Contacting specialists will help avoid complications and cure the disease in the early stages.

Children have different pupil sizes

Why is one pupil larger than the other in a child? The occurrence of anisocoria in a child is a sign of a pathological state of the nervous system and is not caused by drowsiness or increased excitability of the child, but by congenital factors. Concomitant diseases include strabismus and drooping eyelids.

Reasons for changing pupil size:

1. Brain injury.
2. Brain swelling caused by meningitis, encephalitis.
3. Eye injury with damage to the iris.
4. Poisoning certain types poisons
5. Overdose medicines.
6. Brain tumor.
7. Adie's syndrome.
8. Heredity.

It should be borne in mind that sometimes children are born with a deviation. Manifestations of anisocoria are common for them. If the condition is stable and there is no effect on the quality of vision, there is no concern.

If the child’s condition exhibits the following symptoms: decreased visual acuity, double vision, deterioration in health, the parents go to the hospital.

You can often observe situations where a child born with normal pupils changes his condition, the reasons being previous infections or injuries. The unexpected occurrence of anisocoria is a cause for concern and a visit to the doctor.

If a young child is injured by hitting his head hard, it is necessary to check the condition of the pupils. If there is a deviation in the size of one of them, you should urgently call a doctor. He will rule out a concussion in the child, and if confirmed, he will prescribe the correct treatment.

Why does a baby have dilated pupils?

The infant may also have a history of anisocoria. Most often, babies are born with it. If the deviation in size is less than 0.1 cm, the situation is considered normal.

The causes of anisocoria in newborns are:

1. Hereditary factors. There is no reason to worry if the parent also suffers from anisocoria.
2. Weak muscular system. The muscles of the iris do not work well. Dimming the lighting in a healthy state causes the pupil to dilate. When disrupted, the pupil changes in size simultaneously with the second one, and then faster.
3. Taking medications. Many eye drops reduce the sensitivity of the iris. The level of illumination ceases to be a stimulus for contraction and dilation of the pupil.
4. Injury. Infants may show pupils of different sizes to others after a head injury, a fall from a small height, or a birth injury.
5. Compression of the nerve of the eyeball. It can have a lot of consequences, among which anisocoria is the most harmless. Increased pressure inside the skull can lead to more severe consequences.
6. Serious internal diseases in infants: hemorrhage, oncology, carotid artery thrombosis, meningitis.

Video

Diseases that cause different pupils

A change in the size of only one pupil is caused by a number of diseases:

• inflammation of the iris - iritis;
• infections;
• injuries;
• brain tumors;
• Horner's syndrome, in which anisocoria increases in complete darkness;
• Eydi syndrome, in which accommodation is impaired and the quality of vision sharply decreases;
• migraine;
• thyroid cancer, accompanied by enlarged lymph nodes, thrombosis of the carotid artery.

Horner and Eydie syndromes are not very common, so their symptoms are unfamiliar. With Eydie syndrome, the dilation of the pupil when moving the gaze occurs extremely slowly. This leads to impaired accommodation and decreased visual acuity. Often observed in women at a young age.

Horner's syndrome is caused by lung cancer; at the same time, there is weight loss in the hands and impaired sweating in the face. The pupils react normally to light; in the dark and with distance from the light source, anisocoria intensifies.

If you notice that there has been a change in the size of one pupil, you should immediately consult a doctor for diagnosis and treatment. If you miss the moment, you can trigger a serious internal disease, for which anisocoria was only a symptom.

The problem may be a symptom of a dangerous disease

If such a condition appears, you should visit a doctor as soon as possible to exclude the development of the disease.

You should be especially careful if, in parallel with anisocoria, the following are observed:

• fever;
• decreased vision;
• double vision;
• fear of light;
• attacks of nausea;
• Pain in the eyes;
• vomit.

In itself, the changed size of only one pupil rarely causes any inconvenience other than aesthetic ones. The symptoms of the conditions that caused the disease cause more inconvenience.


If anisocoria is a physiological condition, the main symptoms will be:

• pronounced manifestation in the dark;
• preserved and correct reaction to exposure to light;
• disappearance of symptoms when using pupil dilating drops;
• the difference in pupil size is no more than 1 millimeter.

If the cause of anisocoria is Horner's syndrome, then the symptoms will include:

• an increase in the difference in pupil sizes by more than 1 millimeter;
• slower dilation of the affected pupil in the dark;
• pupillary reactions are very slow;
• the sweating system does not work properly.

This damage to the nervous system is accompanied by a large number of symptoms that can be easily identified. If you suspect problems with your body's systems, you should immediately visit a doctor.

Another cause of anisocoria is oculomotor nerve palsy.

If this problem occurs, you should pay attention to the following symptoms:

• weaker dilation of one of the pupils;
• eye movement is limited;
• lack of pupil reaction to light, there is a response to movement;
• when the eyeball deviates, the upper eyelid rises;
• pain when moving the eyeball.

Sometimes anisocoria can be characteristic reaction to take medications: pilocarpine, atropine, adrenaline, naphazoline. This list is quite large; when choosing a product, you need to carefully read the instructions for the drug.

When using some formulations, symptoms may be as follows:

• lack of reaction of the dilated pupil to light;
• absence of other pathological changes in the iris;
• near vision impairment.

Among the reasons causing uneven changes in the size of one pupil are: mechanical influences, surgical interventions. Everyone knows why this is dangerous.

You should pay attention to the following symptoms:

• the pupil is dilated, the reaction to light is lost;
• Slit lamp examination confirms the presence of injury.

Necessary diagnostics, medical history

The search for the causes of the disease and ways to eliminate it always begins with collecting an anamnesis. The age of development of the pathology and the degree of manifestation of signs of anisocoria are determined. Simple photographs help well in the diagnostic process. It is important that they must be done before the onset of the disease.

In addition, the mandatory examination should include the following points:

• determining the nature of changes in the pupils in the light;
• examination of pupils in the dark;
• CT scan;
• determining the speed of reaction to light;
• determining the level of symmetry;
• angiography;
• ultrasonography.

What to do and how to treat the problem

If the diagnosis has confirmed the physiological causes of anisocoria, no special treatment is required. This form of the disease does not affect the functioning of the visual system and general state body.

If a change in the size of one pupil is pathological, you should first determine the cause, and only then begin treatment. Ideally, it will take place in a specialized institution. At the same time, doctors prescribe a course antiviral drugs, immunomodulators, antibiotics.

If the cause of anisocoria is a brain or thyroid tumor, you must surgical intervention. It is important that surgery will also be necessary for glaucoma.

If a diagnosis such as anisocoria is made, it is strictly forbidden to independently carry out therapeutic measures, including the use of drops that change the size of the pupil.

If you ignore the change in size of one pupil, the consequences will be quite severe. In some cases, they can threaten health and life.

It is easier to prevent any disease than to treat it. This also applies to anisocoria. The main way prevention is the use of protective equipment sports activities, use of chemicals.

How to make one pupil dilate more than the other

There is one sure way to make one pupil enlarged. For this you can use Atropine drops. It will provide paralysis of accommodation.

For some types of studies, this particular drug is used, since it allows the fundus to remain at rest. Use it yourself this remedy it is forbidden.

Since ancient times, people have understood that changing the size of the pupil matters, although they did not always understand what it was. Fairy tales speak of “eyes as wide as saucers,” “eyes jumping out,” and eyes “turning into dots from hatred.” All this is a description of the process of changing the size of the pupil for one reason or another.

Our ancestors clearly understood that certain feelings could cause expansion or contraction:

• Love;
• hatred;
• sexual arousal;
• astonishment.

Such capabilities of the human pupil can be skillfully used. For example, before, magicians, when performing their tricks, carefully watched the eyes of the viewer, understanding the degree of severity of the reaction. And men used to skillfully determine the fact of female infidelity by the dilated pupils of their wife.

The human pupil is a precise instrument that allows us to determine the mental and physical state of a person. This only applies to cases where health is normal. In case of pronounced disorders, a change in only one pupil cannot serve as a reliable indication of the state of mind.

5 / 5 ( 7 votes)

Probably, every person who notices in himself or someone close to him that one pupil is larger than the other will immediately panic and begin to ask questions about what this means, is it dangerous, is it necessary to seek help in such a situation? medical care, and how to react to such a phenomenon. Modern medicine has fully studied this deviation and gives recommendations on what to do.

general information

A pathology in which one pupil is larger than the other has scientific name- anisocoria. This unusual condition can occur in both adults and children. The pupil is round hole in the center of the iris. When exposed to light, it has the ability to change its size with the help of muscles. If a person has a pathological condition in the body or directly in the eye apparatus, the pupils can change dramatically: the left one can be narrowed, and the right one can be very dilated. With a sharp expansion, they can become huge or, conversely, small.

Causes

Anisocoria in children

The explanation for the different pupil sizes may be a congenital or hereditary anomaly. Under such circumstances, the disease is called anisocoria. Many parents of newborns encounter this pathology; as a rule, the anomaly in the baby goes away within a few months, and if the defect remains, it does not cause any physical discomfort in the child. If the pathology is accompanied by severe symptoms, a detailed medical diagnosis is needed. The following symptoms should alert you:

With such a deviation, the child may feel unwell.

• double vision;
• headaches, dizziness;
• bad feeling.

It also happens that a child was born with identical pupils, but due to an illness or mechanical injury the size of the pupil changes: one is more dilated, and the second looks smaller, or sometimes it suddenly changes location. And also an unexpected enlargement of the pupil or, conversely, when it is much smaller, may mean that the body is signaling the development of diseases such as cerebral edema or tumor, meningitis, encephalitis.

If the size of one pupil differs slightly or greatly from the other (higher/lower, larger/smaller), multi-colored irises and severely drooping eyelids are observed, these may be signs of Horner's syndrome. This disease tends to occur in both children and adults. Occurs as a result of mechanical injuries to the facial nerve, with acute osteochondrosis of the spine, during an inflammatory process in the brain or spinal cord.

Causes of occurrence in adults

The principles of eye pathology in children and older people are not much different. Enlargement, expansion or pathological change one of the pupils in the eyes may indicate the presence of serious disorders in the body, and the cause of inflammation thus signals the following serious diseases:

This symptom can develop in an organ with myopia.

• Myopia. This is a vision defect in which the pupil size is small or much larger in the affected eye.
• Holmes-Ady syndrome. When a person's pupil dilates in one eye and remains in this position for more than one month, but at the same time he retains a weak ability to respond to light signals. It is characterized by high sensitivity to the elements of pilocarpine. This condition does not bring any feeling of discomfort, so it can only be discovered by chance.
• Damage to the oculomotor nerve. The pupil of the left or right eye has sharply enlarged, there is no reaction to light. This means that the optic nerve is compressed and may respond with abnormalities such as ptosis, diplopia and paresis.
• Injuries. An enlarged pupil can occur as a consequence of traumatic shock when the ocular sphincter or its nerve endings are damaged. The occurrence of such a pathology is possible as a result of an ophthalmic operation, a penetrating wound or mechanical trauma to the eye.
• Pharmaceutical mydriasis. It sometimes happens that one pupil is wider than the other due to long-term use of medications, in cases of complex treatment of acute eye diseases.
• Inflammation of the iris of the visual organ. With this pathology, the pupil of one of the eyes is greatly enlarged, the person feels a burning sensation and discomfort in the area of ​​the eyeball, and photophobia appears.

Pupil functions

In this article

The pupil is located in the center of the iris of the eye, and its size can vary depending on lighting conditions. Its main function is to protect the retina from large quantity light rays. Therefore, in bright light the pupil contracts, and in dim light it dilates. The constriction of the pupil is reflexive - a person does not need to think for any action to occur with the pupil. The pupils of both eyes can simultaneously dilate not only in response to dim light, but also to stress, strong emotional arousal, anger, or due to the use of medications.

The size of a person's pupil depends on individual characteristics optical system of the eye. People with large eyes tend to have large pupils. It is important that they are the same size and can reflexively respond to changes in light levels. If one eye has a larger pupil than the other, this indicates that visual system changes have occurred. Which ones?

One pupil is larger than the other: reasons

Very often, myopic people notice that their eyes are not the same, and the pupil of one eye is larger than the pupil of the other.

The likelihood of this condition increases if the refraction of the eyes is very different. An eye with greater myopia may have a dilated pupil due to excessive visual strain. This condition is temporary and passes quickly. If you notice that the pupils of both eyes are too different, and one of them does not reflexively react to light, then you need to visit not only an ophthalmologist, but also a neurologist to get an accurate picture of your health, since the causes of the pathology can be serious.

One pupil is larger than the other - reasons:

• Physiological - the pupil of one eye may be larger if a child or adult has experienced a stressful situation or the dilation of the pupil has been affected by taking medications.
• Congenital pathologies - it happens that the pupil is large in only one eye, while the other is of normal size, and this may be due to disturbances in the structure of the iris, dysfunction of the nerves that control the extraocular muscles, etc.
• Ophthalmological pathologies - the pupil can become large as a result of severe eye fatigue, especially if there is a strong difference in refraction, myopia, astigmatism.
• Others - tumor processes, eye injuries, brain injuries, infectious diseases, diseases of the nervous system.

Since there are many reasons why one pupil is small and the other is large, a comprehensive diagnosis will be required. You should not hesitate to visit a doctor, as some dangerous diseases appear asymptomatically. Vision at the same time for a long time may remain normal, but it will quickly become bad if treatment for the disease is not started in a timely manner.

The child has different pupils - what to do?

A slight difference in the size of the pupils in adults and children is a physiological norm. If the difference is significant, then it may be associated with congenital anomalies, and not only the pupil, but also visual acuity may differ. Different pupil sizes in children also occur due to underdevelopment of the eye apparatus and are often accompanied by strabismus. Such diseases are diagnosed early childhood. If you notice that one pupil of a schoolchild is larger or significantly smaller than the other, you should urgently visit a doctor, since such a pathology may be associated with brain injury, tumor, retinal diseases, or damage to the optic nerve.

To exclude dangerous pathologies complex diagnostics is required.

Methods for diagnosing diseases of the pupillary reflex

Since diseases of the pupillary reflex, in which the size of one pupil may be smaller or larger than the other, are often associated with the functioning of the brain, the diagnosis is carried out by both an ophthalmologist and a neurologist. First of all, it is determined whether the pupils react to bright lighting. If one pupil does not have such a reaction, this may indicate damage to the midbrain or tension of the oculomotor nerve.

The main methods for diagnosing diseases in which one pupil becomes large:

• study pupillary reactions using an intense light source;
• measurement of intraocular pressure;
• ultrasound diagnostics;
• CT scan;
• studies of the reaction to accommodation with convergence.

During the examination, it is clinically important to establish which eye is in a pathological condition. Anisocoria (different pupils) can be observed when taking medications, traumatic hematomas and hemorrhages that put pressure on the visual centers.

Anisocoria in myopia: features of pathology

The pupils may have different size- one pupil is significantly larger than the other if a person has an ophthalmological problem such as anisometropia. With this pathology, the refraction of the left and right eyes is very different, and therefore the visual organs are subject to excessive stress even when corrected with glasses and contact lenses. Correction with contact lenses is the most preferable, as it is possible to achieve the highest possible visual acuity with an optimal level of patient comfort.
If you have myopia with a pronounced difference in the refraction of the eyes and you notice that the pupils differ in size, for example, one is larger than the other, be sure to visit an ophthalmologist for advice. It may be possible to get rid of the problem correct selection corrective optics.

Due to eye strain due to myopia, against the background of insufficient or incorrect correction, many ophthalmological problems arise, including spasm of accommodation, impaired outflow of intraocular fluid, increased eye pressure, etc. The main task of a person diagnosed with myopia is to constantly take care of the health of the visual organs, which consists of performing a set of therapeutic and preventive measures.

Anomaly of the pupils due to myopia - treatment and prevention

The development of anisocoria in myopia can be prevented by paying due attention to the prevention of the disease. To prevent the pupil of one eye from becoming larger than the other, it is necessary to reduce the strain on the eyes, improve blood circulation and metabolism in the organs of vision. How to do it?
Treatment and prevention of anisocoria, if one pupil becomes larger than the second due to myopia:

• taking eye vitamins with lutein;
• eye drops whose action is aimed at restoring protective functions eyes, improvement of metabolic processes, nutrition of tissues of important eye structures;
• daily exercises for the eyes - a special set of exercises will help relieve spasm of accommodation, improve visual acuity and strengthen the accommodative muscle;
• hiking, swimming, exercise bikes and other useful physical activities allowed for myopia.

If the pupil of an eye with severe myopia is larger than the second one, this may indicate insufficient or incorrectly selected correction. A consultation with an ophthalmologist will help you understand the cause of this condition and find a solution to the problem. The main thing is not to delay visiting a specialist, even if your vision has not become worse, so that the health of your eyes cannot be harmed by disorders that can be successfully treated with timely diagnosis.