Squint, or strabismus, is a condition where the two eyes do not point in the same direction at the same time — one eye may turn in, out, up, or down while the other looks straight ahead. It can be constant or come and go, and can be present from infancy or develop later. It is most often diagnosed in childhood but can affect adults as well.
Symptoms
- Eyes visibly not lined up with each other
- One eye drifting in, out, up, or down
- Double vision (more common when it develops in adults)
- Squinting or closing one eye in bright light
- Tilting or turning the head to see more clearly
- Reduced depth perception
- In infants, mild eye drifting can be normal in the first few months but should be checked if it persists
Causes & risk factors
- Uncorrected refractive errors, especially long-sightedness (hyperopia), in children
- Problems with the control or strength of the eye muscles
- Family history of squint
- Other underlying eye conditions such as cataract or, rarely, tumours inside the eye
- Premature birth or certain developmental conditions
- In adults: stroke, diabetes, thyroid eye disease, or head injury affecting eye-muscle nerves
Diagnosis
- Comprehensive eye examination including vision testing
- Cover test to detect and measure the degree of misalignment
- Assessment of eye movements and how the eyes work together
- Examination of the back of the eye to rule out other causes
- Further tests or imaging if a nerve, muscle, or brain-related cause is suspected
Treatment options
- Glasses to correct any underlying refractive error (can fully correct some childhood squints)
- Patching the stronger eye to treat associated lazy eye (amblyopia)
- Vision therapy/eye exercises for certain types
- Prism lenses to help align images from both eyes
- Eye muscle surgery to adjust and realign the eye muscles when needed
When to seek urgent care
A squint that appears suddenly in an adult, especially with double vision, drooping eyelid, or other new neurological symptoms, needs prompt medical evaluation as it can signal an underlying nerve or brain condition. In a child, a squint together with a white or unusual reflection in the pupil needs urgent same-day eye examination. Otherwise, a stable childhood squint should be assessed at a routine but timely paediatric eye appointment.
Frequently asked questions
Will my child outgrow their squint?
Some mild drifting in very young infants can settle on its own, but a persistent or noticeable squint after a few months of age should be evaluated — it does not reliably go away by itself and early treatment gives the best results for vision development.
Why does squint need early treatment in children?
In young children, the brain can start to ignore the image from the misaligned eye, leading to lazy eye (amblyopia) and permanently reduced vision in that eye if untreated. Treating it early protects vision development.
Is squint surgery painful or risky?
It is a commonly performed, generally safe procedure done under anaesthesia to adjust the eye muscles; your surgeon will explain the specific risks and recovery for your situation.
Can adults develop a squint?
Yes — new squint in an adult can result from conditions like diabetes, thyroid eye disease, stroke, or head injury, and often causes double vision, so it should be evaluated by an eye doctor.
Ready to see us?
Call the appointment desk, or book online — we will confirm your time by phone.
Sources consulted: AAO — What Is Strabismus?, NHS — Squint (Strabismus) . General medical information — not a substitute for professional diagnosis. Content pending final medical review by BSEH doctors before publish.
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