Strabismus – Strabismus: Causes, Symptoms, Types, Diagnosis, Associated Conditions and Treatment

It is a defect in vision that affects the ability of the eye to coordinate movements when focusing on objects.

Offering two asymmetric views, imperfectly aligned eyes often cause a defective depth perception and are associated with disorders such as crossed eyes, strabismus, walleye, and heterotropia.

Without proper treatment of strabismus, these conditions may worsen and certain aspects of vision may be permanently affected.

The term strabismus refers to a person suffering from strabismus.

Causes of strabismus

Strabismus differs from refractive errors, such as myopia, hyperopia and astigmatism. In some cases, the inability of the eyes to focus symmetrically can be attributed to problems with the muscles that control eye movement.

More commonly, however, strabismus is the result of problems in the brain . The brain may have problems fusing the two images it receives from the eyes and, in rare cases, a tumor may be affecting its ability to process visual information.

Children often experience strabismus as a result of problems that can easily be treated with glasses. There is also evidence that the condition can be hereditary.


The different types of strabismus produce a variety of symptoms.

Depending on the orientation of the eye or the misaligned eyes, people suffering from this disorder may have difficulty concentrating on objects or judging distances, they may also experience double or blurred vision.

The detection of symptoms is the first step to determine if surgery is advisable as strabismus treatment.

Perhaps the most obvious symptom is a crossed eye, or a single eye that leans visibly to the left, right, up or down and can not coordinate movements with its partner. Squinting in children can also be a sign of this condition.


Depending on how the vision is interrupted, strabismus can take several different forms. Once the doctors have accurately diagnosed what form is involved, the best treatment plan for strabismus can be determined.

If the affected eye or eyes always show an inability to coordinate movements properly, the condition is known as constant strabismus. If the problems only occur episodically, it is considered intermittent.

Another disorder, the esotropia, occurs when both eyes are turned inward, resulting in crossed eyes.

If the turn of the eyes is oriented outward instead of inward, the disorder is known as exotropia.

Children who experience this condition often seem to be daydreaming or not paying attention. Another type of strabismus is hypertropia, in which symmetric vision is inhibited by excessive upward orientation of one or both eyes.

Finally, a complicated condition known as Duane syndrome affects the ability of the eye to perform normal lateral movements to and from the nose.

Here, the problem is not that an eye is abnormally tilted, but that it does not turn enough when the gaze moves to the right or to the left.


The diagnosis of strabismus should occur as soon as possible and, of course, before a child reaches the age of two.

It is advisable that all children receive a checkup when they are between six and nine months of age, and ideally never more than one year of age.

When the child is more than two years old, strabismus treatment becomes difficult, and even strabismus surgery is often ineffective.

In addition to carefully looking for visible signs such as unruly, crossed, or divergent eyes, doctors will consider a child’s medical history when trying to determine if an eye disease, uncorrected vision, or other condition is causing symptoms.

Conditions associated with strabismus

One of the results of strabismus is double vision, which occurs when two uncoordinated eyes do not focus on the same object.

As a result of this inability, two separate and slightly out-of-series views of the world are transmitted to the brain, which makes patients see everything twice.

However, while double vision is often caused directly by strabismus, it may have other origins. Therefore, its presence does not necessarily require strabismus treatment.

Likewise, many symptoms that initially suggest the presence of this condition, such as divergent, misaligned or converging eyes, may also indicate unrelated conditions that require their own special course of treatment.

Any comprehensive diagnosis will involve ruling out conditions often mistaken for strabismus, which include amblyopia (lazy eye), cataracts, exophoria, and Graves’ disease .


The treatment of strabismus ranges from being as simple as correcting the sight of children with glasses and a relatively simple vision therapy to a more complex strabismus surgery.

Intermittent strabismus, for example, can usually be treated effectively with eye patches, special glasses and visual therapy.

Over time, such basic treatment usually allows the brain to control eye movements and surgery is not required.

In cases of constant strabismus, the surgical option can be recommended. However, since there is no guarantee that it actually improves vision, this is generally considered a last resort.