Squint (strabismus) surgery
An operation that adjusts the muscles that move the eye, to straighten a squint (turned eye) and help the eyes work better together.
✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review
In short
- Squint surgery adjusts the eye muscles to straighten a turned eye and help the eyes work together; it is reconstructive, not cosmetic.
- It can relieve double vision, restore some binocular and 3D vision, widen the field of view and improve appearance — but results are not perfectly predictable.
- A notable proportion of people need a further operation over time because of under- or over-correction or the squint drifting back.
- Serious complications are rare; double vision and a red eye for a while afterwards are common, and children almost always need a general anaesthetic.
A plain-English summary. The detail — including risks and recovery — is below.
At a glance
A general guide. Your surgeon will give you advice for your situation.
Straightens the alignment of the eyes
Squints better managed first with glasses, prisms or treatment for a 'lazy eye' (amblyopia).
The eye is red, sore, gritty and watery. Use prescribed drops and pain relief, avoid rubbing, and rest. Some double vision is common as the brain adjusts.
Orthoptic review to check alignment and binocular vision as the eye settles.
The eye is red, sore, gritty and watery. Use prescribed drops and pain relief, avoid rubbing, and rest. Some...
Discomfort eases and most children return to school and many adults to work. The eye is still visibly red. Avoid...
Redness fades substantially and any double vision often improves. Avoid swimming until the eye has healed and your...
The eye looks normal again and the surgeon assesses the final alignment and whether any further treatment, glasses...
What is squint (strabismus) surgery?
A squint (strabismus) is when the eyes do not point in the same direction — one eye may turn in, out, up or down. It can cause double vision, eye strain, problems with 3D vision, an abnormal head posture, and difficulties with confidence and everyday interaction. It affects children and adults.
Squint surgery adjusts the small muscles that move the eye. The surgeon can weaken a muscle (by detaching it and reattaching it slightly further back), strengthen a muscle (by shortening it), or move where it attaches, to rebalance the pull on the eye and bring it straighter.
The Royal College of Ophthalmologists describes straightening the eyes as a reconstructive procedure, not a cosmetic one: it aims to restore normal alignment and, where possible, binocular (two-eyes-together) vision, relieve double vision, and improve the field of view, as well as appearance. In children it is often part of treating the developing visual system; glasses, prisms or treatment for a 'lazy eye' (amblyopia) may be needed first or as well.
It is important to be realistic. Squint surgery improves alignment but the result is not perfectly predictable, and a significant number of people need more than one operation over time.
Types & techniques
There isn't one single operation. The right approach depends on you — which is something to discuss with your surgeon.
Squint surgery vs botulinum toxin injection
| Feature | Squint surgery | Botulinum toxin |
|---|---|---|
| How it works | Repositions eye muscles | Temporarily weakens a muscle |
| Lasting effect | Often longer-lasting | Temporary, may need repeating |
| Anaesthetic | Usually general | Injection, often awake |
| Best suited to | Larger or stable squints | Some smaller or changing squints |
| Adjustability | Adjustable sutures in some adults | Wears off over weeks/months |
Not every squint suits every treatment. Your surgeon or orthoptist will advise based on the type, size and cause of the squint and your age.
Preparing for your surgery
- Have a full assessment by the eye team (including an orthoptist), who measure the squint, often on more than one visit, before planning surgery.
- Make sure any glasses prescription and any 'lazy eye' (amblyopia) treatment are sorted first, as these can change the picture.
- For children, prepare them gently for a hospital day and a general anaesthetic, and follow fasting instructions carefully.
- Tell the team about all medicines, allergies and previous eye surgery, as earlier squint surgery makes repeat surgery more complex.
- Arrange a lift home and time off work or school (often around 1–2 weeks).
- Expect the eye to be red and sore for a couple of weeks, and have pain relief and any prescribed drops ready.
- Discuss realistic goals: straighter eyes, relief of double vision and better binocular vision where possible, and the chance of needing more than one operation.
What happens
Squint surgery is almost always done under general anaesthetic in children and most adults, so you or your child are asleep; a local anaesthetic is used only occasionally in selected adults. It is usually a day case.
The surgeon gently moves the eye to reach the muscles on its surface, working through the thin clear membrane (conjunctiva) over the white of the eye — they do not remove the eye from the socket. They then weaken, strengthen or reposition one or more muscles and secure them with dissolvable stitches, before closing the membrane, usually with dissolvable stitches too. In adjustable-suture surgery, the final position is fine-tuned shortly afterwards while you are awake.
The operation usually takes around 45–90 minutes depending on how many muscles are adjusted. Afterwards the eye is red and sore and may water; most people go home the same day with pain relief, drops and clear instructions.
Is this operation right for me?
A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.
May not be suitable if…
- Squints better managed first with glasses, prisms or treatment for a 'lazy eye' (amblyopia).
- Small or unstable squints that may suit botulinum toxin or observation instead.
- An eye where surgery would risk troublesome double vision that cannot be managed, needing careful assessment first.
- A child or adult not fit for the anaesthetic until other health issues are addressed.
- Unrealistic expectations of guaranteed perfect, permanent alignment from a single operation.
Delay surgery if…
- There is an active eye or eyelid infection.
- The glasses prescription or amblyopia treatment has not yet been optimised.
- The squint measurements are still changing and need to stabilise.
- A child or adult is unwell or not fit for a general anaesthetic.
- You need more time to weigh up the chance of further surgery and the goals of treatment.
Alternatives to discuss
- Glasses or prisms to manage the squint or double vision without surgery.
- Treatment for a 'lazy eye' (amblyopia), such as patching, in children.
- Botulinum toxin injection to weaken an eye muscle temporarily.
- Orthoptic exercises in selected types of squint.
- Watchful waiting if the squint is small, stable and not troublesome.
Before you decide
Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.
What matters most to me?
Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.
What are all my options?
Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.
What would make me pause?
Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.
What happens if I do nothing today?
For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.
Anaesthetic choices
The safest option depends on the operation, your health, the facility and your surgeon/anaesthetist. Ask what is planned and why.
Benefits
- Straightens the alignment of the eyes
- Can relieve or reduce double vision
- Can restore some binocular (two-eyes-together) and 3D vision where the visual system allows
- Can widen the useful field of view and reduce the need for an abnormal head posture
- Can improve appearance, confidence and social interaction
- In children, supports the developing visual system as part of wider treatment
Risks & complications
- A red, sore, gritty and watery eye for a couple of weeks
- Double vision for a time after surgery while the brain adjusts to the new alignment
- Mild irritation or allergy to the stitches
- Some swelling and visible redness over the white of the eye
- Under-correction (some squint remains) or over-correction (the eye turns the other way), which can need further surgery
- The squint drifting back over months or years
- Persistent double vision that needs glasses, prisms or further treatment
- A small cyst or lump, or a thicker scar, where a muscle was reattached
- A slipped or lost muscle, affecting eye movement and needing further surgery
- Serious infection, or perforation of the wall of the eye during surgery
- Bleeding or infection inside the eye, which can affect vision
- A lasting effect on vision (very rare)
The most important things to understand are that the result is not perfectly predictable and that a further operation is needed in a meaningful number of cases. Double vision after surgery is common and usually settles, but occasionally persists. Serious sight-threatening complications are rare. For children, the general anaesthetic is part of the discussion, though the risk in a healthy child is low. Ask your surgeon about your or your child's likely number of operations and the plan if double vision continues.
Published figures to discuss
Outcomes depend on the type, size and cause of the squint, whether it is longstanding, and whether earlier surgery has been done, so success and reoperation rates vary widely. The Royal College of Ophthalmologists and UK studies provide useful figures, but they describe groups of patients rather than predicting any one person's result.
| Figure | Reported range | How to interpret it | Source / confidence |
|---|---|---|---|
| Serious adverse events and complications overall | Around 1 in 400 operations (Royal College of Ophthalmologists) | Squint surgery is considered very safe; most complications are minor and temporary. | Recovery of fusion and stereopsis after adult strabismus surgery — study (PMC)ncbi.nlm.nih.govPublished figure |
| Needing a further operation (under- or over-correction or drift) | Reported in roughly 1 in 5 to 1 in 2 of patients across studies | Varies widely with the type and complexity of the squint; the result is not perfectly predictable. | Recovery of fusion and stereopsis after adult strabismus surgery — study (PMC)ncbi.nlm.nih.govPublished figure |
| Perforation of the wall of the eye during surgery | Rare; about 0.08% in a UK study of around 24,000 squint operations | Usually managed at the time; serious consequences are uncommon. | Recovery of fusion and stereopsis after adult strabismus surgery — study (PMC)ncbi.nlm.nih.govPublished figure |
| Severe infection | Rare; about 0.06% in the same UK study | Minor surface infection is more common but usually settles with treatment. | Recovery of fusion and stereopsis after adult strabismus surgery — study (PMC)ncbi.nlm.nih.govPublished figure |
These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.
Recovery — what to expect, and when
Recovery is usually straightforward but the eye looks dramatically red at first. The eye looks straighter immediately, while redness and soreness settle over a couple of weeks and the final alignment is judged over the following weeks to months.
- A very red, sore, gritty and watery eye for the first couple of weeks
- Double vision for a while as the brain adjusts to the new eye position
- Mild swelling and visible redness over the white of the eye
- Itchiness or mild allergy from the stitches as they dissolve
- The eye gradually looking and feeling normal over a few weeks
Aftercare
- Use all prescribed drops or ointment (antibiotic and/or anti-inflammatory) exactly as directed.
- Give regular pain relief, especially in the first days, and use cool compresses for comfort if advised.
- Do not rub the eye, and keep soap, shampoo and dirty water out of it while it heals.
- Avoid swimming and dusty or dirty environments until your surgeon says it is safe.
- For children, keep them off rough play and follow the advice on returning to school.
- Attend all follow-up appointments so the alignment and any double vision can be checked.
- Report increasing pain, spreading redness or any drop in vision urgently.
- Lift home and time off work or school (about 1–2 weeks) arranged
- Pain relief and any prescribed drops/ointment collected
- Cool compress materials ready if advised
- Follow-up appointment booked
- For children: school and carers informed
- Plan agreed for managing any double vision (glasses/prisms) if it persists
- Clinic's urgent/out-of-hours number saved in case of pain or vision change
Scars and how they heal
Squint surgery is done through the thin clear membrane over the white of the eye (the conjunctiva), not through the skin, so there is no scar on the face or eyelid. The eye is very red where the surgery was done, which usually settles over a couple of weeks. Occasionally a small lump, cyst or a thicker patch of scar tissue forms over the white of the eye where a muscle was reattached, and a little pinkness can persist for some months.
⚠ Get urgent help if…
- Increasing or severe eye pain rather than the expected soreness easing
- A sudden drop in or loss of vision
- Spreading redness, swelling of the eyelids, or thick discharge (possible serious infection)
- A high temperature with an increasingly red, painful eye
- Double vision that is getting worse rather than settling
- Any of these in the days and weeks after surgery should prompt urgent contact with your eye team
Who to contact: your surgeon or clinic first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.
General guidance — it doesn't replace the specific advice your surgeon gives you.
Results & realistic expectations
A good result is straighter, better-aligned eyes, relief or reduction of double vision, and — where the visual system allows — better use of the two eyes together, a wider field of view and improved confidence. The eye looks straighter immediately, with the final alignment judged once redness and swelling settle over the following weeks to months.
It is important to understand that the result is not perfectly predictable. Some squint may remain, the eye may be slightly over-corrected, or the squint may drift back over time, and a further operation is needed in a meaningful number of cases. Surgery improves alignment and binocular function where possible, but cannot guarantee perfect alignment for life.
Many people get a long-lasting improvement from squint surgery, but the alignment can drift over months or years, particularly in longstanding or complex squints, and some people need one or more further operations. In children, the developing visual system and any changing glasses prescription also affect the long-term result. Ongoing follow-up with the eye team helps pick up and manage any drift.
Combining with other procedures
Squint surgery is often one part of wider eye care that includes glasses, prisms, treatment for a 'lazy eye' (amblyopia) and sometimes botulinum toxin injections. The order matters — for example, a glasses prescription and amblyopia treatment are usually optimised first. Your surgeon and orthoptist will explain how surgery fits with the rest of the plan.
Follow-up & long-term care
You or your child will be reviewed after surgery to check healing, the alignment and any double vision, with further visits over the following weeks and months as the result settles. Because the alignment can drift over time, longer-term follow-up is often arranged, especially in children. Report increasing pain, spreading redness or any vision change immediately.
- Keep follow-up appointments, as alignment can change over time and may need further treatment.
- Keep glasses prescriptions up to date, as these affect eye alignment, especially in children.
- Continue any prescribed treatment for a 'lazy eye' (amblyopia).
- Seek review if a squint, double vision or an abnormal head posture returns.
- For children, attend routine sight and eye-development checks.
Revision and secondary surgery reality
- A further operation is needed in a meaningful proportion of people because of under-correction, over-correction or the squint drifting back.
- Repeat surgery can be more complex because of scarring from the first operation.
- Double vision that persists may be managed with glasses or prisms rather than immediate further surgery.
- In children, changing glasses and the developing visual system can affect whether more surgery is needed.
Ask your surgeon for their own revision rate, what counts as a revision, and what is included in the written aftercare policy.
What good aftercare looks like
- Orthoptic review to check alignment and binocular vision as the eye settles.
- A clear plan for managing any double vision with glasses or prisms if it persists.
- A named contact route and written warning signs for infection and vision change.
- Longer-term monitoring for drift, especially in children, with an agreed plan if a further operation is needed.
- For children, coordination with their wider eye care, glasses and any amblyopia treatment.
What affects the cost
Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:
- How many eye muscles need adjusting and whether one or both eyes are operated on
- Whether adjustable-suture surgery is used
- The anaesthetic (general anaesthetic adds cost, especially for children)
- The surgeon's experience and seniority
- The orthoptic assessments before and after surgery
- Whether follow-up and any further surgery are included, and the complexity of any repeat operation
- Whether the price includes the orthoptic assessments before and after surgery
- Whether the anaesthetic and day-case facility fees are included
- Whether follow-up appointments are included
- The named operating surgeon
- What happens, and what it costs, if a further operation is needed for under- or over-correction
- What happens, and what it costs, if double vision persists and needs glasses, prisms or more treatment
- What happens, and what it costs, if a complication occurs
On the NHS? Squint surgery is routinely funded by the NHS as a reconstructive procedure for children and adults when clinically appropriate; private care may be chosen for timing or choice of surgeon.
You're entitled to your total cost in writing — including aftercare and any revision — before you decide.
Consent traps and marketing red flags
These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.
Consent traps
- Believing the result is guaranteed or that one operation will always be enough.
- Not being warned that double vision is common early on and can occasionally persist.
- Treating the operation as purely cosmetic and overlooking its functional aims and benefits.
- Not optimising glasses or amblyopia treatment before considering surgery.
- For children, no clear discussion of the general anaesthetic and what to expect.
Marketing red flags
- Promising perfect, permanent alignment from a single operation.
- Framing squint surgery as a purely cosmetic 'eye straightening' treatment.
- Not mentioning the realistic chance of needing further surgery.
- Down-playing the common early double vision and red eye.
- Quoting a single headline price with no follow-up or repeat-surgery plan.
Choosing a surgeon safely
- Check your surgeon is on the GMC Specialist Register for this area.
- Make sure they practise at a CQC-registered location, and look for membership of bodies like BAAPS or BAPRAS.
- You're entitled to a two-stage consent process with time to reflect (a cooling-off period). The surgeon who will operate must consent you — not a salesperson.
- Be wary of pressure: time-limited offers, discounts or deposits taken before you've had time to think are red flags, not bargains.
- You're entitled to your total cost in writing — including aftercare and any revision — before you decide.
Questions to ask your medical professional
Take this to your consultation. A good surgeon will welcome every one of these.
- What type and size of squint do I (or my child) have, and what is causing it?
- What is the realistic chance of needing more than one operation?
- How likely is double vision afterwards, and what is the plan if it persists?
- Which muscles, and one or both eyes, will you operate on, and why?
- Should glasses, prisms, amblyopia treatment or botulinum toxin be tried first or alongside?
- How will the result and any later drift be monitored, and who do I contact urgently after surgery?
- Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
- Will you be the surgeon who carries out my operation, and who looks after me afterwards?
- What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
- What does a realistic result look like — and what can this operation not achieve?
- What are my options, including waiting, doing nothing for now, or choosing a different approach?
- Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
- What is the total cost in writing, including any follow-ups, and how much time do I have to decide?
Frequently asked questions
Is squint surgery available on the NHS?
Is squint surgery just cosmetic?
Will I have double vision afterwards?
Will one operation be enough?
Does my child need a general anaesthetic?
How red and sore will the eye be?
Find a verified surgeon for squint (strabismus) surgery
Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.
No verified consultants list this procedure yet — browse the full directory.
How we made this page
Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →
Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.
Sources & standards: NHS — Squint (strabismus) Royal College of Ophthalmologists — Adult strabismus surgery in the UK (indications, evidence and benefits) Moorfields Eye Hospital — Strabismus Recovery of fusion and stereopsis after adult strabismus surgery — study (PMC)
Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.
Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.
Related guides: Cataract surgery · Corneal transplant · Cosmetic eyelid surgery (blepharoplasty) · Droopy eyelid surgery (ptosis correction) · Glaucoma surgery (trabeculectomy)