Understanding “Lazy Eye” (Strabismus): What Parents Need to Know — Part 2

Written By Irina Yakubin

Approximately 1 in 20 children in the United States has some form of strabismus. Yet many families are unfamiliar with the medical term — and instead use the phrase “lazy eye.”

As discussed in Part 1, “lazy eye” can refer to two different conditions:

  • Strabismus

  • Amblyopia

In this article, we’ll focus specifically on strabismus — what it is, why it happens, and how it’s treated.

What Is Strabismus?

Strabismus is a misalignment of the eyes.

Instead of both eyes pointing in the same direction, one eye may turn:

  • Inward (esotropia)

  • Outward (exotropia)

  • Upward (hypertropia)

  • Downward (hypotropia)

The turn may be:

  • Constant

  • Intermittent (comes and goes)

  • Present in one eye or alternating between eyes

Strabismus can appear in infancy, childhood, or even adulthood.

⚠️ A sudden new eye turn — especially in adults — requires urgent medical evaluation.

What Causes Strabismus?

Eye alignment depends on:

  • Six extraocular muscles

  • Three cranial nerves

  • Complex coordination within the brain

A disruption anywhere along this pathway can result in misalignment.

Common Risk Factors

1. Genetics
Children with a family history of eye turns are at increased risk.

2. Uncorrected Refractive Error
Certain refractive errors — especially significant farsightedness — can trigger inward eye turns in children.

3. Neurological or Medical Conditions
In adults, a sudden onset of strabismus may signal:

  • Nerve palsy

  • Stroke

  • Tumor

  • Other neurological disorders

Sudden double vision or new misalignment should never be ignored.

How Is Strabismus Diagnosed?

Parents are often the first to notice an eye turn — especially in photographs or when a child is tired.

However, a comprehensive eye exam is essential to:

  • Measure the degree of misalignment

  • Determine whether it is constant or intermittent

  • Assess binocular vision (how the eyes work together)

  • Evaluate for associated amblyopia

If an eye turn “comes and goes,” mention this during the exam — intermittent turns still matter.

Why Is Strabismus a Concern?

When a child develops strabismus early in life, the brain may suppress input from the turned eye to avoid double vision.

Over time, this suppression can lead to amblyopia.

If both eyes turn simultaneously, the brain struggles to establish stable binocular vision.

If the eyes alternate, amblyopia risk may be lower — but depth perception and binocular coordination may still be affected.

Strabismus impacts more than appearance. It can affect:

  • Visual development

  • Depth perception

  • Reading performance

  • Confidence and social interaction

How Is Strabismus Treated?

Treatment depends on the cause and severity.

Options may include:

Glasses
Correcting refractive error alone may significantly reduce or eliminate the eye turn.

Patching
Used if amblyopia is present.

Vision Therapy
Structured exercises to improve coordination and control.

Surgery
In some cases, eye muscle surgery may be recommended to improve alignment.

Often, treatment involves a combination approach.

Key Takeaway

Strabismus is not simply a cosmetic issue.

It is a condition that can disrupt visual development and binocular function — especially in children.

Early detection improves outcomes dramatically.

If you notice an eye turn — even occasionally — schedule a comprehensive eye exam.

Irina Yakubin
Next

Understanding “Lazy Eye” (Amblyopia): What Parents Need to Know — Part 1