Condition

Squint (strabismus)

Medical reviewer Mr Mohamed Mohyudin, Consultant Ophthalmic SurgeonArticle reviewed

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Squint (strabismus) at a glance

Side-view diagram of the eye with the eye muscles highlighted: the part of the eye involved in a squint.
Where it affects the eye: Eye muscles. Simplified side view of the eye. It shows location, not how severe a condition is.
Part of the eye
Eye muscles
Common signs
  • One eye turning in, out, up or down
  • Eyes that do not appear to move together
  • Double vision, especially in adults
  • A child screwing up the eyes or turning their head to look
Condition group
Eyelid conditions

What is a squint (strabismus)?

A squint is a misalignment of the eyes, so they do not look in the same direction at the same time. It is common in young children. In children the brain may learn to ignore the image from the turning eye, which can lead to amblyopia, while in adults a new squint often causes double vision.

Symptoms of a squint

A squint may be constant or come and go, for example when tired.

  • One eye turning in, out, up or down
  • Eyes that do not appear to move together
  • Double vision, especially in adults
  • A child screwing up the eyes or turning their head to look

What causes a squint, and who is at risk?

A squint can be present from birth or develop later. It can be linked to long-sightedness, problems with the eye muscles or the nerves controlling them, a family history, or other underlying conditions. A new squint in an adult should be assessed promptly.

How is a squint treated?

Treatment depends on the cause and age. It may include glasses to correct long-sightedness, patching to treat any associated lazy eye, eye exercises, and surgery to adjust the eye muscles and align the eyes. Treating children early gives the best results for vision.

Practical guides

Children's eye healthVision screening, spotting a squint, and sensible screen-time habits for growing eyes.

Treatments & Surgery

Amblyopia treatmentPatching, glasses, or eye drops that help a weaker eye develop better vision in childhood.Vision therapyStructured eye exercises and training for convergence problems, amblyopia and some squints.Strabismus surgerySurgery to adjust eye muscles and improve alignment in children and adults with a squint.ROP treatmentLaser, injections or surgery for severe retinopathy of prematurity when screening finds treatable disease.

Frequently asked questions

Can a squint be treated?

Yes. Depending on the cause, treatment may include glasses, patching for an associated lazy eye, eye exercises, or surgery to align the eyes. Early treatment in children gives the best results.

Is a squint just a cosmetic problem?

No. In children a squint can affect vision development and lead to a lazy eye, and in adults it can cause double vision, so it is worth having assessed rather than treating it as cosmetic only.

Should a new squint in an adult be checked?

Yes. A squint that appears suddenly in an adult, especially with double vision, should be assessed promptly, as it can occasionally signal an underlying problem that needs attention.

Your next step

Take this to your appointment

Write down what has changed, when it started, your current medicines and the questions you want answered. Take these to your eye-care appointment.

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Sudden loss of sight, severe eye pain or a dark curtain across vision needs immediate assessment. Do not wait to complete a worksheet.

Sources for this information

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