Types of Squint (Strabismus): Symptoms & Causes Explained

Introduction

Squint is misalignment of the eyes such that the right and left eyes are pointed in different directions. Though it is a common condition among younger populations, affecting 2 to 4 percent of children, it may also appear later in life.The misalignment may be permanent or it may be temporary, occurring occasionally. The deviation may be in any direction: inward, outward, upward or downward. If the child is not treated at the appropriate time, a condition called amblyopia occurs, which eventually leads to permanent loss of vision

What is Squint?

A squint or strabismus happens when both eyes do not look in the same line at the same time. One eye may turn in, out, up, or down while the other stays straight. It can appear always or only sometimes, depending on how the person focuses or feels tired. Early checking and care can help balance the eyes and protect proper vision. Many people often ask what squint is, as it not only changes how eyes look but also affects clear sight if ignored.

Types of squint 

Esotropias

Squint often starts with esotropia, a condition where one eye turns inward toward the nose. This convergent squint affects alignment and can lead to vision issues if not addressed early. In children, it shows up as crossed eyes during focus. Parents notice the eye drifting in while playing or reading. Doctors check for this through simple eye exams.

Exotropias

Squint types include exotropia, known as a divergent squint. Here, one eye turns outward, away from the nose. This misalignment happens more when looking far or being tired. It disrupts clear vision and can cause double images. Common in kids, it appears during outdoor activities. Signs include the eye wandering out when not focusing. Causes linked to muscle control weaknesses. 

Hypertropias and Hypotropias

These affect balance and cause head tilts to see better. They fall under broader squint types with unique traits. Kids might rub their eyes or squint to focus. Treatments vary by cause, from prisms to operations. Each type needs tailored care. Understanding these helps families seek help fast. Vertical shifts demand prompt attention to avoid fatigue.

Paralytic Squints

Causes of squint eye often tie to paralytic squints from nerve damage. Three cranial nerves control the six eye muscles: the third, fourth, and sixth. Poor blood flow, pressure, or head injuries harm them. This limits eye movement and creates a squint. The affected eye fails to track properly. Symptoms include double vision and droopy lids. In children, it follows accidents.

Restrictive Squints

Squint eyes in children can stem from restrictive squints, where muscles or the eye socket restrict motion. Mechanical blocks prevent normal turns in certain directions. Thyroid disease commonly triggers this by swelling tissues around the eye. Squint eye signs include limited side glances and pain on movement. It differs from nerve issues in feel.

Symptoms of Squint (Strabismus) 

Squint can cause a person to lose focus, strain the eyes, or develop double vision. Early identification of signs makes treatment easier and more effective.

Misaligned eyes

The most visible sign is when the eyes point in different directions. One eye may stay straight while the other turns. This uneven look can be more obvious in bright light. It is one of the earliest squint eye signs noticed by parents or friends.

Double vision

Many people experience double vision because both eyes send different images to the brain. This may cause blurred or overlapping sight. The condition may come and go, depending on stress or tiredness, making clear vision tough to maintain.

Eye strain and headaches

Due to uncoordinated eye movement, the brain works harder to merge two different images. This often leads to headaches, pain around the eyes, or trouble focusing for long hours. Frequent discomfort should not be ignored.

Poor depth perception

A person may struggle to judge distances correctly, making daily tasks like pouring water or driving difficult. Lack of depth awareness often points toward squint development and needs attention to avoid worsening visual balance.

Turning or tilting the head

To focus better, individuals might turn or tilt their head unnaturally. This helps them use their stronger eye more efficiently. It is often seen in children who are developing squint symptoms without realizing it.

Causes of Squint (Strabismus)

There are different reasons behind squint formation. These causes may begin from birth or may develop later due to habit, illness, or injury.

Muscle weakness

One of the main reasons for squint is uneven strength of the eye muscles. Weak muscles cannot guide both eyes to move together properly, leading to poor alignment. Understanding such causes of squint eye helps in planning correct eye exercises and treatments.

Nerve problems

Sometimes the nerves that control eye movements do not send proper signals. This failure affects how the eyes are positioned or focused. Such nerve-related problems are usually noticed after illness, trauma, or long-term fatigue.

Refractive errors

A strong difference between the focusing power of both eyes can cause squint to develop. The brain begins to depend on one eye more than the other, and the unused eye drifts out of line. Corrective glasses often help reduce this imbalance.

Genetic factors

Some people inherit family patterns of squint. If parents or close relatives had it, a child may have a higher chance too. Many such conditions appear early in life and show a relation with squint types observed in the family.

Eye injury or illness

Any accident or eye infection affecting muscle strength can also lead to squint. At times, after surgery or illness, the eye fails to return to normal coordination. Such conditions explain why squint occurs unexpectedly in some individuals.

Refractive errors

Acquired squints are sometimes caused by the eye’s inability to focus light that passes through the lens. This is known as a refractive error. These include myopia (shortsightedness), Hyperopia (Long-sightedness) or Astigmatism (cylindrical power).

Other causes

Although most squints are idiopathic or caused by refractive errors, in rare cases they are
the result of:
• Childhood illnesses, for example viral infections such as measles, although it is possible these illnesses simply accelerate a squint that would have developed anyway
• Some genetic conditions, such as Down’s syndrome
• Hydrocephalus, which is caused by find a build-up in the brain
• Lazy eye (amblyopia) - when the brain starts to ignore signals coming from the eye with the squint
• Other eye problems, such as abnormal development of the muscles that move the eye, or a problem with the retina (the layer of light-sensitive nerve cells at the back of the eye)

Common Risk Factors for Developing Squint

Although most squints are idiopathic or caused by refractive errors, in rare cases they are the result of:

Genetic Factors

Squint often runs in families, pointing to a clear genetic link. If parents or siblings have this eye condition, the chance goes up for children. Doctors see patterns where eye muscles do not align right from birth. This happens because genes control how eyes work together. Early checks help spot issues before they grow.

Issues in Children

Squint eye in children shows up early, often before age five. Babies sometimes have temporary turns, but real cases need care. Kids rub their eyes a lot or tilt their heads to see clearly. This comes from weak eye focus during growth. Play and school tasks suffer if untreated. Parents notice when one eye drifts in play. 

Types of Misalignment

Squint types include inward, outward, or up-down shifts in eye position. Each type affects how light hits the retina. Inward turns happen more in far views, while outward ones strike closer work. Vertical shifts are rare but tricky. These forms link to muscle imbalance. 

Muscle and Nerve Problems

Causes of squint eye tie back to eye muscle weakness or nerve signals gone wrong. Muscles pull the eyes in sync, but damage disrupts this. Head injuries or strokes can trigger shifts. Nerves from the brain to the eyes falter in some cases.

How Squint is Diagnosed: Tests and Procedures

Sight tests

Different tests can be used to help diagnose a squint and assess the level of vision. These will vary according to your age, but may include:

• Concentrating at a light
• Matching letters and pictures
• Reading a letter chart
• Looking at visual targets at different distances, first with one eye covered and then the other

Retina and optic nerve examination

A retina and optic nerve examination helps the doctor find any internal eye condition or damage leading to misalignment. This test, ruling out hidden reasons, becomes vital to confirm structural eye health. In some squint types, nerve weakness or retinal issues create focus problems, and this exam ensures that such internal causes are treated properly before any correction starts.

Refraction

Refraction testing identifies the exact lens power needed for clear vision. The doctor uses drops or ointments to relax the focusing muscles for accurate results. When light is not properly bent inside the eye, it may lead to vision strain or misalignment. It is often seen as a cause of squint eye, especially in children with untreated farsightedness.

Ocular movements test

During this test, the doctor checks how smoothly and equally both eyes move in all directions. Any abnormal motion helps find out the imbalance causing misalignment. It also helps in deciding treatment for different squint types based on movement patterns and control. The test is simple and painless, but it gives important clues about coordination issues.

Synoptophore

The Synoptophore test measures the eye’s alignment by showing two separate images to each eye through two tubes. You are asked to focus on both pictures together. The device measures how the eyes coordinate and detect misalignment levels. Often, it helps doctors understand why squint occurs and what type of therapy, exercise, or surgery may be needed later.

Also Read: What Is Glaucoma? Symptoms, Causes, Treatment & Prevention

Eye exercises for squinting eyes

Eye exercises help in training the eye muscles to move and focus together. They are generally done along with other treatments like glasses or eye therapy. These exercises slowly build up control over weak muscles and make it easier to use both eyes at once. Doing them daily brings steady improvement and better focus for many people.

Pencil push-up exercise

This simple exercise helps the eyes to move inward and focus together. Hold a pencil at arm’s length and slowly bring it closer to your nose while keeping both eyes fixed on it. This strengthens focus and helps improve alignment. It is often used in mild cases to correct squint eyes in children and adults, too.

Eye tracking exercise

Place an object in front of you and move it slowly in all directions. Try to follow it with only your eyes, keeping your head still. This exercise trains both eyes to track motions evenly and reduces strain. Eye tracking also improves coordination over time.

Focus shifting exercise

Look at a near object for a few seconds and then switch your focus to something far away. Repeat this movement several times. This exercise improves the flexibility of the eye muscles and makes focusing easier. It also lessens fatigue caused by prolonged screen use.

Mirror fixation exercise

Stand before a mirror and look directly into your own eyes. Try to align both eyes by making them focus straight ahead. It helps in improving control and self-awareness while practicing daily. Many find it a motivating and easy habit to build.

Dot card exercise

A dot card with small dots arranged in a line is used for this practice. Hold the card touching your nose and look down the line, trying to align the images into one. It builds depth awareness and helps eyes learn proper alignment for better teamwork.

FAQ

Q1. Is Squint the Same as a Lazy Eye?

No, these two terms are not the same. Squint happens when the eyes do not point in the same direction. One eye might turn in or out. A lazy eye, or amblyopia, means the brain ignores signals from one eye. It leads to poor vision in that eye. Squint can cause lazy eye if not fixed early. 

Q2. Can Squint Cause Vision Loss?

Yes, squint can lead to vision loss over time. When eyes misalign, the brain favors the straight eye. The turned eye gets less use. This weakens its vision. In children, it may cause permanent lazy eye. Adults face double vision or strain. Untreated squint strains eye muscles. 

Q3. How Can I Fix Squint Eyes Naturally?

Fixing squint eyes naturally takes patience. Start with eye exercises. Pencil push-ups strengthen muscles. Hold a pencil at arm's length. Focus as you bring it close. Do this daily. Cover the strong eye sometimes. It forces the weak one to work. Warm compresses relax muscles. 

Q4. What Treatments Are Available for Squint?

Several treatments fix squint. Glasses correct vision issues first. They align eyes for many. Prism lenses shift images. They reduce double vision. Eye patches cover the strong eye. This trains the weak one. In kids, it stops lazy eye. Botox injections relax tight muscles, a temporary fix for adults. 

Q5. How Soon Should Squint Be Treated in Children?

Treat squint in children as soon as you spot it. The ideal time is before age seven. The brain develops faster than. Early fix prevents lazy eye. Delays make vision loss permanent. Notice if one eye drifts. Kids may squint to see. School photos show it. Take to the eye doctor right away, tests confirm the issue. 

Q6. When Should I See an Eye Specialist for Squint?

See an eye specialist for squint if your eyes misalign often. In kids, go at the first sign. Like head tilting or closing one eye. Adults seek help for headaches or double vision. Sudden changes need an urgent visit. Routine exams spot hidden issues. Family history means earlier checks. 

Q7. Does Eye Surgery Treat Squint Eye Permanently?

Eye surgery for squint eye often gives lasting results. It adjusts eye muscles to align properly. Many patients keep their eyes straight after. But not always permanent. Some need follow-up fixes. Age and cause affect outcomes. Kids recover fast. Vision improves long-term. 

Q8. What Are Some Effective Exercises for Squinting Eyes?

There are many eye exercises for squint that actually help the muscle control and focus. Common ones include pencil push-ups, visual tracking, and fusion tasks. These exercises work best under supervision from an eye expert, as they train the eyes to move correctly and maintain balanced coordination.