English: strabism


Squint is the deviation of an eye from the direction in which it should look naturally. This means that one eye looks at an object, i.e. fixates it, while the other eye looks past the object. An object is therefore not viewed by both eyes at the same time.

Squinting in children

About 3% of all children cross-eyed during their childhood. This can have an impact on later visual skills. This is due to the child's immature brain. It classifies the incorrect image information of the cross-eyed eye as incorrect. As a result, the brain suppresses this information. As a result, the information from the cross-eyed eye is less represented in the brain. This can lead to poor vision in later life. That is why it is so important to recognize the child's squint early enough and to act on it promptly.

In children, one can differentiate between early childhood strabismus and so-called normosensory late strabismus:

  • The early childhood squint is often accompanied by restrictions in spatial vision, latent eye tremors, head tilt and certain (squint) movements of the eye in certain situations.Therefore one speaks of an early childhood squint syndrome.
  • A normosensory late squint is usually characterized by a sudden appearance and the seeing of double images.

As in any age, strabismus can occur in the context of underlying diseases. Infections, such as a measles virus, can also trigger a squint. But that is rather rare. Squinting in children can be very obvious or barely noticeable.

If a squint angle of less than 5 degrees is measured, it is called "micro-squint" or "microstrabismus". This type of squint usually has no effect on spatial vision, but if left untreated, it can also lead to poor vision. There are often other accompanying complaints. Some children complain of burning eyes, increased sensitivity to light and / or headaches. Obvious, but barely noticeable, squint can lead to concentration problems and poor reading. This can lead to school problems in children, which are often misinterpreted. Blinking, winking and clumsiness when grasping objects or frequent stumbling can also be indications of squint syndrome. With obvious squint, the children also often suffer from teasing from their classmates.

It is important to check the child's vision. In the case of very young children, one observes the behavior in order to draw conclusions about the ability to see. For children over 3 years of age, there is an opportunity to find out their visual acuity in the game. The earlier the strabismus is discovered and treated, the lower the risk of weak vision.

Is squinting normal in babies?

Many babies squint because their eyes first have to learn to interact. So-called baby squint is completely normal up to the age of 6 months. In addition, parents often suspect their baby is cross-eyed. But often it is just an "apparent squint". This is due to the baby's usually still wide bridge of the nose. This causes the whites of the eyes to be much smaller towards the nose than towards the temple. This creates the impression that the baby is squinting inward.

This impression can be intensified, especially with Asian babies, with uneven lighting or when the baby looks to the side. Parents can distinguish “apparent squint” from “real” squint by looking at photos. The corneal reflexes of the flashlight reveal whether a visit to the ophthalmologist is necessary: ​​if the reflexes are symmetrical, there is no squint, if they are uneven, then an ophthalmologist should be consulted. This can then differentiate which form of strabismus is present and whether and which treatment is necessary.

So-called secondary strabismus often occurs in babies up to the age of 4. There is no disturbance of the eye muscles. The concomitant squint is a normal phenomenon in the course of developing eye coordination and visual skills. In principle, the cross-eyed eye accompanies the movement of the healthy eye. The exact causes have not yet been fully explored. As a rule, the accompanying strabismus does not require any surgical intervention. In some cases, farsightedness is what triggers the concomitant strabismus. This should be ruled out by an ophthalmologist.


Squint is a deviation of one eye from the normal line of sight while the other eye looks straight ahead. An object is therefore only ever fixed by one eye. Those affected have one weak eye and one better eye. As a rule, fixation is done with the better seeing eye.

Strabismus can be viewed from different angles: direction of the squint, occurrence of the squint (early or late in life) and the cause of the squint.
For example, there are:

  1. Inside and outside squint
  2. Early childhood squint and
  3. Late squint.

There are various possible causes. Most of the time, however, no trigger can be identified. Symptoms include fatigue, headaches, and double vision. An important consequence of squinting that must be treated at an early stage is weak vision.
The diagnosis is made using open and cover tests. The therapy should first clarify whether there is farsightedness, which can then be compensated with the help of glasses. To train the weaker eye, the better one is covered with a plaster. The squint operation is also available as a treatment measure.

Strabismus should be treated as early as possible to prevent vision loss. This represents permanent damage. The squint itself cannot be prevented.


The squint can be judged and classified according to different points of criticism:

  1. according to the direction of the deviation
  2. for the cause of the squint
  3. according to the time of occurrence (strabismus acquired early or late)

manifest squint
At the Squint one eye is always to be called the leading eye, namely that which fixes an object. If you cover this now, the other eye adjusts itself to the object and fixes it now. This is called manifest squint. Furthermore, the manifest strabismus can be divided into external and internal strabismus. If the adjustment movement of the uncovered eye takes place from the outside (the eye therefore moves from the temple direction nose) so one speaks of external squint. If the eye adjusts itself in the reverse order (from the inside to the outside), one speaks of internal strabismus.
With manifest strabismus, the eyes can also be different in height. Adjustment movements of the uncovered eye can also be observed here.

latent squint
A latent squint is when the uncovered eye does not make an adjustment movement. The eye that has just been released, however, makes an adjustment movement.

Concomitant squint
Concomitant squint is also known as concomitant squint. The squint angle between the two eyes always remains the same. The cross-eyed eye follows the healthy, fixing eye, so to speak. A typical example of this is that early childhood internal strabismus.

Incomitant squint
In contrast to concomitant strabismus, the squint angle is not constant here. The angle is different in different directions of view. An example of this is a Paralysis of an eye muscle.

Forms of squint

Early childhood squint syndrome
The early childhood Squint occurs in the first 6 months of life. There must be other, for example neurological causes (neurology) be excluded. Presumably there is a developmental defect that prevents seeing with both eyes. The brain so cannot merge the image of the right and the image of the left eye into one. It is the most common form of squint.

Normosensory late squint
This form of squint occurs after the 1st year of life. The See having two eyes is already mature. There is no defect in any development-related system. An operation must be performed immediately to maintain the ability to “see with both eyes” so that only one image is created in the brain. This form of squint is much rarer.

There are also forms of strabismus of other origins, such as Eye muscle paralysis. Squinting does not always have to take place in an immediately recognizable, large squint angle: micro-squint describes a one-sided squint with a very small angle.
You can also squint vertically, so-called vertical squint. Not every child who looks like they are cross-eyed actually does cross-eyed. In some children, a wide bridge of the nose can only fake squinting. The “white” in the eye appears larger on one side than on the other. A very simple method to exclude a squint, which the parents can also use, is this Corneal reflexes to compare. When illuminating the eyes from a light source coming straight ahead and in front, the reflections should be symmetrical. If this is the case, there is no squint. However, further clarification should be carried out with an ophthalmologist (specialist in ophthalmology), as untreated or treated too late strabismus can lead to serious long-term effects.

root cause

The Cause of squint varies depending on the type of squint. In other words: every type of squint has a different cause. In the case of concomitant strabismus, often no cause can be found. Incomitant squint types, on the other hand, can definitely be explored.
Squint can therefore have many different causes. For example, can Muscleswho move the eye will be paralyzed. For this Paralysis there are again various causes.


When is an operation necessary?

In order to maintain binocular vision, a prompt operation is advisable for normosensory late strabismus. It is recommended to have the operation performed no later than 6 months from the time of occurrence. The aim is to restore the parallel eye position to make it possible to see completely with both eyes. In early childhood strabismus, the ability to see, two-eye vision and spatial vision are first conservatively promoted. Surgery is often recommended in preschoolers.

Course of the operation

In preliminary examinations, the ophthalmologist carries out various measurements of the squint angle, tests of the mobility of the eye and tests of the ability to see with both eyes. It is precisely analyzed which eye needs to be operated on and to what extent the eye muscles need to be changed. Before the operation, adequate information about the operation and the anesthesia should be given by a doctor and anesthetist. This also includes information about regulatory measures that should be observed and the limits and possibilities of the operation.

In children, the operation is usually performed under general anesthesia. On the other hand, a local anesthetic is usually sufficient for adults. The operation involves correcting the affected eye muscles. Usually two muscles of the eye are changed at a time. As in other parts of the body, there are always so-called muscle pairs on the eye that perform opposite movements. This means that one eye muscle is responsible for ensuring that the eye looks to the left, while the so-called opponent ensures that the eye can look to the right. The aim is to create a balance between the eye muscles and thereby bring both eyes back to parallel. One speaks here of a combined squint operation. First, the conjunctiva of the eye is opened to get to the eye muscles. Then the insertion of one muscle is shifted back while the opponent in the same eye is shortened.

Only the outer eye is operated on. The inside of the eye remains untouched. Regular checks are carried out after the operation. The eye is often slightly red after the procedure and can cause itching. In rare cases, double vision can occur, but this disappears after a few days. If you are unsure, the doctor should be asked.

After a squint operation, the person concerned is usually on sick leave for 2 weeks. Bathing, swimming and sauna should be avoided for at least a week. To support the healing process, the doctor usually prescribes eye drops and an eye ointment.

Surgery complications

The squint operation only affects the outer eye. Therefore, it is usually low-risk. Inflammation and bleeding can rarely occur postoperatively. In some cases, the squint is under- or over-corrected so that double vision, for example, can still be present.

Only under certain circumstances, in very rare cases, complications can endanger the ability to see and the eyesight.

Can you train squinting away?

Depending on the shape of the squint, it is possible to correct the squint yourself through so-called fusion training. Special visual exercises are repeated regularly. These exercises are designed to train the eyes so that they are able to combine the images of both eyes into one image. This training can be effective with mild latent squint.

With pronounced squint and the manifest form of squint, the training is not sufficient to correct the squint.

Another training option for mild latent squint is what is known as occlusion therapy. The healthy and cross-eyed eyes are masked alternately for a while. In some cases it is also possible to mask off the respective lens. This forces the cross-eyed eye to see. This method is particularly used with children. The chances of success depend on the type of squint and individual influences.


The symptoms of a cross-eyed person include, among other things, slight fatigue, since seeing is strenuous, a headache and double vision can also exist. Sometimes patients have blurred vision.
If there is a paralysis strabismus, for example, a nerve is damaged that normally has one Eye muscle those affected complain about nausea and dizziness. Patients often try to compensate for the misalignment of the eye by tilting the head.

Consequence of squinting
It will Squint not treated in time, the result is a weak vision (Amblyopia). This is the most common and most serious complication of strabismus Childhood. There is always a risk of weak-sightedness when the cross-eyed child eye for fixation (i.e. for seeing) is preferred. The other eye does not usually fixate spontaneously. With squint forms, in which both eyes are used alternately to see, so to speak, so there is no preferred eye here no Weak-sightedness.
With cross-eyed children, you have to ensure that both eyes are used equally and equally often. This can be achieved by alternately taping one eye of the children with a plaster (see also therapy). The most important goal in squint therapy is to prevent or remedy weak vision, not to treat the squint position.


The weak-sightedness of an eye is irreversible (irreversible) damage and must be prevented as the primary goal!


Is there a suspicion Squint, one can compare the corneal reflexes of both eyes for orientation. They should usually be symmetrical. The patient is allowed to fixate a light source, creating a light reflex on the corneal surface. If the light reflex does not appear in the same place, there is strabismus.

Furthermore, open and cover tests are suitable for diagnosis.

Covering test
With a cross-eyed person one always considers one of the eyes to be the leading or fixing one. This is covered first. One expects an adjustment movement of the cross-eyed eye. If you cover the cross-eyed eye, there is no adjustment movement because this eye is already fixed. If only one eye appears, one-sided squint is present. Double-sided squint is also possible.
If the adjustment movement is made from the outside, there is external squint. If the eye works from the inside out, there is an internal squint.

Not only covering one eye can provide information about strabismus. The rediscovery can also be interpreted. If you had covered the leading eye, it will make a jerky compensatory movement to fix it when you uncover it. If there is no squint, the eye will not move you even after uncovering it.


The prognosis of squint depends on the shape of the squint, the cause and many other factors. In general, the earlier the strabismus was recognized and treated, the better.

If the early childhood strabismus is discovered too late, it can lead to weak eyesight in the children. This occurs because only one eye (the fixating eye) is primarily used and the impressions of the other, cross-eyed eye are, so to speak, suppressed by the brain.
This eye then becomes weak-sighted. The weak vision of the eye is irrevocable.


There is no way to prevent squinting. However, if it is recognized early, it can be treated well.

Is strabismus hereditary?

Squint is very likely to be inherited. If a parent is cross-eyed or has been treated for it, a newborn baby should be examined as soon as possible. In addition to the hereditary predisposition, other factors can also influence the occurrence of strabismus.

Squinting when tired

When tired, a so-called latent squint can occur. This is usually harmless.It is a sign that the eye muscles are not in balance and are working together. However, it is possible for the brain to compensate for this. As a result, a squint is not permanently visible and both visual information can be combined into one impression by the brain. However, this compensation costs energy and effort and can lead to fatigue. If you are tired, this strategy can often not be maintained. A temporary squint results.

This brief squint may sometimes be accompanied by headache, double vision, or blurred vision or dizziness. Often there is no need for treatment. If necessary, fusion training can be useful. In some cases there are visual disturbances that should be clarified by an ophthalmologist.