Overview of Squint

Squint meaning in Urdu (Bhenga hona / بھینگا ہونا) refers to a condition due to the misalignment of both eyeballs. One eyeball is inwards, upwards, downwards, or outwards direction while the other focuses on one spot. It is also known as strabismus or crossed-eyes.

Squint can be caused by problems with eye muscles, and affects the brain nerves that control the eye muscles. It is also associated with other conditions such as diabetes, high blood pressure, multiple sclerosis, myasthenia gravis, or thyroid disorders. It can be seen either at a specific part of the time (intermittent squint) or all the time (constant squint).

Prevalence of Squint

In Pakistan squint is more common in children between the ages of 6-15 years. The overall prevalence of squint in children is about 6.2% according to the total number of patients reported in the tertiary care hospital of Karachi. 

According to different surveys, the global prevalence of strabismus is about 2%-5% in the general population. But it is more common in children and old age people. The incidences of squint vary in each category worldwide as follows:

  • The no of cases reported between the age of 55-75years is about 6.1%
  • For young children cases reported between the age of 1-3 years account for 1.9%
  • The adult cases reported between the age of 4-54 years estimates at 3.3%

Signs and Symptoms of Squint

General symptoms of squint or strabismus may involve:

  • Misaligned eyeballs
  • Eyes are not able to move together 
  • Frequent blinking or squinting, especially in bright sunlight 
  • Moving the head in different directions for looking at the things
  • Poor depth perception 
  • Double vision

Symptoms of Squint in Children

The squint can be a congenital condition, present at the time of birth or appearing 6 months after the birth. The sign of a squint is observed at an early age in which the direction of the eyes is changed. Another sign is double vision. This is observable when one eye is closed and one turns the head in different directions for looking at the objects.

As the squint is left untreated then it leads to amblyopia or lazy eye, in which the brain is not transmitting signals to one of the eyes. Therefore, most doctors may recommend an eye patch over the eye to improve vision. Sometimes childhood squints can recur in adulthood.

Types of Squint

The following terms refer to the strabismus according to the different positions of the eye:

  • Hypertropia produces when the eye turns in an upward direction
  • Hypotropia produces when the eye turns in a downward direction
  • Esotropia or convergent squint results when the eye turns in an inward direction 
  • Exotropia or divergent squint results when the eye turns into an outward direction

Other types of squint are categorized according to the duration, direction, or underlying cause of the squint. Some of them are as follows:

  • Constant and Intermittent Squint- In this type, if the squint appears periodically it is called intermittent squint. But if the squint appears permanently then it is known as a constant squint.

  • Manifest and Latent Squint- Manifest squint occurs when the eye is open while latent squint appears when the eye is covered.

  • Concomitant (non-paralytic) and Incomitant Squint (paralytic)- These types are classified on the specific type of eye muscles. A concomitant squint appears when the angle of the squint remains the same but people can see in all directions. On the other hand, an incomitant squint appears when the angle of the squint changes related to its direction. Incomitant strabismus, or paralytic squint, present in both groups in childhood and adulthood caused by neurological, mechanical, or myogenic problems affecting the eye muscles (controls the eye movements). In comparison to this, concomitant non-paralytic squint is congenital; this means appears in newborns or children.

  • Accommodative Squint- This undergoes in the esotropia type. It is observed in very farsighted children. They have difficulty seeing nearby objects. 

Causes of Squint

Strabismus or squint can be caused in different ways:

  • Congenital, means present when the babies are born
  • Hereditary means, People with this problem may have a family history
  • Due to illness or long-sightedness
  • Formation of the lesion on a cranial nerve
  • Refractive error of the eye means the light cannot focus on the lens of the eye

Other conditions that can cause strabismus or squint:

  • Myopia or short-sightedness is unable to see far away
  • Hypermetropia or long-sightedness in which inability to see the nearby objects
  • Astigmatism, where the shape of the cornea is not curved
  • Hydrocephalus, due to the accumulation of cerebrospinal fluid builds up in and around the brain
  • Viral infections also lead to strabismus such as measles
  • Other conditions include Noonan syndrome and some other genetic conditions such as down’s syndrome

Risk Factors of Squint

The following factors can increase the risk factors of squint:

Complications of Squint 

  • Eventually leading to lazy eye 
  • Losing vision 
  • Having double vision over time 

This condition can also take a toll on mental health which may result in low self-esteem.



There’s no way to reduce the risk of squinting until or unless people wear protective things such as safety goggles during risky activities. Another way to protect it is an early diagnosis of the eye or performing an eye exam regularly for another eye disease. Early treatment can be preventable for squint eyes.



An ophthalmologist will examine the eyes through different tests. In order to prevent vision loss, early diagnosis and treatment of squint are needed. If a person observes the symptoms of squint then immediately perform the following eye test:

  • A corneal light reflex test for examination of squint
  • A visual acuity test is to determine the ability to read from a distance
  • A cover/uncover test for the measurement of eye movement and deviation
  • A retina exam to examine the backs of the eyes

If the physical symptoms of squint appear along with other conditions then a doctor may examine the brain and nervous system as well. This is done by performing different tests such as an MRI or CT scan of the brain.

Squint is most common for newborn babies. A simple eye examination is conducted in which the doctor will test alignment by comparing the position of light reflecting off each eye. As infants are less likely to cooperate that’s why it may be diagnosed by observing their behavior of them. For young children who can cooperate with the doctor for both intermittent and constant squints can be detected by cover or uncover of eyes test and alternating cover tests. These tests examine the response of the child as it stares at one object with covered and uncovered eyes.

Treatment of Squint | When to Consult a Doctor

The squint eye treatment depends on the severity and underlying condition. For example, if a squint eye is caused by a lazy eye, a doctor may suggest wearing a patch over the eye for strengthening the weaker eye muscles. 

Other treatment options may include the following means.

  • Glasses are used for some conditions that cause squints such as hypermetropia, or long-sightedness.
  • In some cases, a  doctor suggests an eye patch on one side of the eye. This will help to improve the vision of the eye.
  • Botulinum toxin injection of botox is injected into a muscle located on the surface of the eye. This eye drop is beneficial when the symptoms of squint appear suddenly without any underlying cause. Botox temporarily supports the eyes to align properly.
  • Surgery is only used when a person doesn’t respond to other treatments. The surgery can easily realign the eyes and restore binocular vision by moving the specific muscles back to a normal position. In some cases, one or both eyes require operation for the right balance of eyes.
  • Eye exercises give internal strength to the squint eyes.

In case you exhibit any concerning signs and symptoms of squint, consult an eye specialist as soon as possible.