What is strabismus (squint)?
- Part of the eye
- Eye alignment
- Group
- Focus & eye coordination
- Vision functions involved
- Alignment and depth
- Main source
- NHS
One eye may turn inward, outward, upward or downward. A squint can affect how the eyes work together, but its effect on sight differs between people. Children do not always report double vision.
Ophthalmologist
A medical doctor who specialises in eye conditions and their treatment.
Orthoptist
A professional who assesses eye movements and how the two eyes work together.
How strabismus (squint) can affect day-to-day life
You may recognise some of these situations, or none of them. The point is to find help with the things you want to do.
Looking between objects
Some people experience double images or adopt a head turn.
Describe when this happens and which direction you are looking in.
Games and reaching
Using both eyes together for depth may be affected.
Discuss practical difficulties with the orthoptist. Finding a task hard does not on its own diagnose a squint.
Social situations
An eye turn can affect confidence even when vision feels unchanged.
Include confidence and comfort when discussing treatment goals.
Changes you may notice
- An eye turn, sometimes more apparent when tired.
- Closing one eye, turning the head or seeing double.
Everyone is different. Symptoms on their own cannot identify a condition.
What to do about a new or sudden changeAssessment and care
An orthoptist or ophthalmologist assesses alignment and vision. Options include glasses, selected exercises, injections or surgery, depending on the cause. Children may also need separate treatment for amblyopia.
One condition does not mean one visual effect
Some people have double vision. Others suppress the image from one eye or have reduced vision from childhood. A doubled scene on a website cannot represent every person's experience.
How vision is affected
These topics explain the parts of vision involved. They do not predict your sight, diagnose anything or show the condition itself.
Alignment and depth
Your brain combines the view from each eye with perspective, size and movement. Judging depth uses several clues at once.
Open the alignment and depth labEveryday support
Seek advice for a constant squint, a recurring squint after three months of age, or a new squint later in life. Sudden double vision needs urgent assessment. Do not use online exercises as a substitute for diagnosis.
A question to take to your appointment
What is the cause, and is treatment intended to improve alignment, double vision, visual development or more than one of these?Prepare your appointment checklist
Sources and review status
Sources checked 4 October 2026. Educational draft, not yet clinically reviewed. No clinician has endorsed this page. Follow the advice of your own eye-care team.
How this content is prepared