Short answer
Laser eye surgery reshapes the cornea (the clear front window of the eye) to reduce short sight, long sight or astigmatism, so that glasses or contact lenses are needed less often.13 The three main approaches are LASIK, surface treatments (PRK, LASEK and TransPRK) and SMILE.1 It does not stop the age-related loss of reading vision (presbyopia), and it carries risks such as dry eye and night-time glare.35 Suitability depends on prescription stability, corneal thickness and overall eye health, which can only be judged by examination.13
| Question | Summary |
|---|---|
| What it treats | Myopia (short sight), hyperopia (long sight) and astigmatism1 |
| What it does not treat | Presbyopia, cataract or other eye disease3 |
| Minimum age | Over 18 with a stable prescription16 |
| Typical treatment range | Up to -10.00D short sight, +4.00D long sight, ±6.00D astigmatism1 |
| Common early effects | Dry eye, glare, haloes, fluctuating vision13 |
| Further surgery | Up to 1 in 10 need an extra procedure1 |
| Serious vision loss | Rare; fewer than 1 in 5000 need a corneal transplant1 |
On this page
- What laser eye surgery is and how it works
- What may be causing blurred vision
- Who may be considered
- Alternatives
- Procedure, preparation and anaesthesia
- Recovery and results timeline
- How long results last
- Pain and comfort
- Risks and complications
- How strong is the evidence?
- Technique distinctions and red flags
- Cost drivers and what a quote should include
- Frequently asked questions
- Bottom line
- Related reading
- Sources
What laser eye surgery is and how it works
Most of the eye’s focusing power comes from the cornea. An excimer laser removes microscopic amounts of corneal tissue to change its curvature, so light focuses more sharply on the retina.12 The techniques differ in how the surgeon reaches the tissue to be reshaped.
| Technique | How it is done | Recovery and trade-offs |
|---|---|---|
| LASIK (laser in situ keratomileusis) | A femtosecond laser cuts a thin flap; an excimer laser reshapes the tissue beneath; the flap is replaced without stitches1 | Fast visual recovery, often back to work next day; flap-related complications possible12 |
| PRK, LASEK and TransPRK (surface treatments) | The surface layer (epithelium) is removed or loosened, the surface is reshaped, and the epithelium regrows over about a week12 | No flap; eye usually very sore for several days; slower recovery1 |
| SMILE (small incision lenticule extraction) | A laser cuts a thin lens-shaped disc inside the cornea, removed through a small incision14 | No flap; surface stays intact; visual recovery may be slower than LASIK; US approval covers short sight and astigmatism14 |
What may be causing blurred vision
Blurred vision is not always a refractive error. Cataract, keratoconus (a condition in which the cornea thins and bulges), glaucoma, severe dry eye and corneal scarring can all affect vision, and the AAO lists each of these as reasons laser surgery may not be appropriate.3 The RCOphth notes that cataract or eye surface problems can make someone unsuitable.1
Age matters too. From the mid-forties, difficulty reading is usually presbyopia, the natural stiffening of the eye’s lens, which corneal laser surgery does not reverse.13 A prescription that is still changing, which is common in young adults, means the result may not last.16
Who may be considered
The RCOphth describes typical candidates as adults over 18 whose prescription has changed by no more than 0.5D in two years, within the ranges in the snapshot above.1 The AAO adds that corneas must be thick enough and healthy, general eye health good, and expectations realistic.3 Suitability tests usually include a full eye examination, measurement of the prescription with and without dilating drops, corneal thickness and shape, tear film assessment and pupil size.356
Who may not benefit or may face additional risk
- People with very high prescriptions, whose results are generally less good.5
- People with large pupils, who are more prone to night-vision symptoms.6
- People with autoimmune disease, poorly controlled diabetes or medicines such as steroids that slow healing.36
- People who play contact sports such as boxing or martial arts.6
When a responsible clinician may advise against it
Alternatives
| Option | Main points |
|---|---|
| Glasses | No surgical risk; may limit some activities and sport1 |
| Contact lenses | Good all-round vision; serious corneal infection affects about 1 in 3000 wearers a year1 |
| Phakic intraocular lens (ICL or PIOL) | Lens implanted in front of the natural lens; often used in younger people outside the laser range1 |
| Refractive lens exchange (RLE) | Natural lens replaced as in cataract surgery; often preferred by older patients1 |
Lens-based options are a different operation, inside the eye, with their own risks. Readers considering lens replacement may find the cataract surgery page useful, because the procedure is very similar.
No treatment is a legitimate option
Laser eye surgery is elective. Glasses carry no surgical risk, and continuing with them or with contact lenses is a reasonable choice.1
Procedure, preparation and anaesthesia
Preparation starts with the suitability assessment described above; contact lens wearers should ask how long to leave lenses out before measurements. The laser stage itself is short; for SMILE the AAO describes about 30 seconds of laser and 10 to 15 minutes overall.4 Someone else needs to drive you home.4
Professional standards in the UK expect the operating surgeon to be involved in assessment and aftercare and to provide continuity of care.9
Recovery and results timeline
| Milestone | LASIK | Surface (PRK, LASEK) | SMILE |
|---|---|---|---|
| Return to work | Often next day1 | Often a week or longer before driving standard1 | Visual recovery may be slower than LASIK1 |
| Exercise | Non-contact from day one; contact sports after at least a month1 | Non-contact from day one; contact sport sooner than LASIK1 | Non-contact from day one; contact sport sooner than LASIK1 |
| Swimming | Usually avoided for a week1 | Usually avoided for a week1 | Usually avoided for a week1 |
Red patches on the white of the eye after LASIK can take up to 6 weeks to clear.1 Visual results at three months are similar across techniques, but the prescription can take up to two years to stabilise fully.1
How long results last
The corneal change is intended to be lasting, but the eye continues to age. Reading glasses are usually needed from the mid-forties, and the FDA notes that in some long-sighted patients the improvement may decrease over time.35 Fine-tuning treatment is sometimes needed; the RCOphth gives up to 1 in 10.1 Previous laser surgery also changes eye pressure readings and lens calculations for future cataract surgery, so it should always be mentioned to eye professionals.1
Pain and comfort
The sources we checked do not describe sensations during the laser stage, so it is worth asking the surgeon what numbing is used and what may be felt. Afterwards, comfort differs by technique. The Cochrane review found LASIK less painful than PRK.7 Surface treatments usually leave the eye very sore while the surface layer regrows over about a week, and lubricating and prescribed drops are used.1 After LASIK and SMILE, gritty or dry sensations are common in the early weeks.13
Risks and complications
| Category | Examples |
|---|---|
| Expected temporary effects | Dry eye, fluctuating or hazy vision, glare, haloes and starbursts, light sensitivity; usually improve over weeks to months13 |
| Recognised complications | Under- or over-correction needing glasses or retreatment; persistent dry eye; night-vision difficulty; corneal haze after surface treatment; flap problems and epithelial ingrowth after LASIK125 |
| Rare serious complications | Corneal infection; corneal ectasia (progressive weakening and bulging); loss of best-corrected vision; corneal transplant in fewer than 1 in 5000123 |
Ectasia is described by NICE as a serious complication that can lead to loss of vision; in studies reviewed for its 2006 guidance, the median rate after LASIK was 0.2%, with some affected eyes thought to have been unsuitable for surgery.2 Careful screening of corneal thickness and shape is the main safeguard.23 Severe dry eye can be permanent in some people.5
How strong is the evidence?
| Claim | Vireon assessment | What supports it | Important limitation |
|---|---|---|---|
| Laser surgery reduces short sight effectively in selected patients | Strong | NICE review of trials and case series; Cochrane review of 13 trials27 | Much data predates current lasers |
| LASIK recovers faster and hurts less than PRK, with similar one-year results | Moderate | Cochrane review7 | Trials mainly in short sight; older techniques |
| SMILE causes fewer dry-eye symptoms than LASIK | Limited | Meta-analysis of six small studies8 | Objective tear tests similar; heterogeneous studies |
| Rate of corneal ectasia | Uncertain incidence | Case series in NICE review2 | Rare event; depends on screening |
| Micromonovision helps reading after mid-forties | Limited | Professional patient information15 | Reduces depth perception; not everyone tolerates it |
Many outcome figures come from case series reported by surgeons, and the NICE guidance dates from 2006. Laser platforms have changed since, so older complication rates may not match current practice in either direction.
Technique distinctions and red flags
LASIK and SMILE both use a femtosecond laser; LASIK creates a flap, while SMILE removes tissue through a small incision with no flap.14 Surface treatments avoid any cut in the cornea but have the most discomfort and slowest recovery.17 Which technique suits an eye depends on prescription, corneal thickness and lifestyle; no single technique is best for everyone.
- Assessment and surgery on the same day with no time to consider risks.
- No discussion of presbyopia or of how reading vision will change with age.3
- Not meeting the operating surgeon before the day of surgery, or no plan for follow-up.9
- Advertising that implies no risk or a fixed result; the FDA advises against choosing surgery because of cost or advertising.5
Cost drivers and what a quote should include
Laser eye surgery is not available on the NHS and is not usually covered by private health insurance.1 Cost varies with technique, whether one or both eyes are treated, and the surgeon and laser platform. The RCOphth notes that fees usually include follow-up and fine-tuning for up to two years.1 A quote should state the pre-operative tests, the named surgeon, drops and medicines, follow-up visits, and the conditions and time limit for any retreatment.
If you are travelling for treatment
- The full assessment, including corneal measurements, must be done in person, ideally on a separate day from surgery.19
- Allow time for at least an early check after surgery; surface treatments need about a week for the surface to heal.1
- Our sources do not give a specific flying interval; ask the surgeon, and carry your drops in hand luggage.
- Arrange an optometrist or ophthalmologist at home who will accept follow-up, and keep a written record of the treatment.1
Questions worth asking a clinician
- Which technique do you suggest for my eyes, and why not the others?
- Are my corneas thick and regular enough, and what were the measurements?
- How will my reading vision change over the next ten years?
- What is the chance I will need retreatment, and is it included?
- Who will see me if I have problems after I return home?
Frequently asked questions
Does laser eye surgery hurt?
Discomfort mainly comes afterwards: surface treatments usually leave the eye very sore for several days, while LASIK causes less pain.17
When can I go back to work and drive?
After LASIK many people return to work the next day, while surface treatments may take a week or longer to reach the driving standard.1
When can I exercise?
Non-contact exercise can usually resume from day one, swimming after about a week, and contact sport at least a month after LASIK.1
Will I still need reading glasses?
Most people will, from their forties onwards, because laser surgery does not correct presbyopia.3
How long do results last?
The change to the cornea is designed to be lasting, but the prescription can take up to two years to settle, and up to 1 in 10 people need a further procedure.1
Is SMILE better than LASIK?
Not clearly: SMILE avoids a flap and may cause milder dry-eye symptoms, but the evidence is limited and visual recovery may be slower.18
Bottom line
For adults with a stable prescription and healthy corneas, laser surgery can reduce dependence on glasses, but presbyopia still arrives and early dry eye and glare are common. The decision depends less on the brand of laser than on careful corneal screening and a surgeon who will be available afterwards.
Related reading
- Eye surgery overview
- Cataract surgery
- How to verify a doctor’s credentials
- Understanding a treatment quote
- Medical travel red flags
Sources
- The Royal College of Ophthalmologists (RCOphth). Laser Vision Correction: Patient Information. RCOphth; n.d. https://rcophth.ac.uk/laser-vision-correction-patient-information Accessed 5 November 2026.
- National Institute for Health and Care Excellence (NICE). Photorefractive (laser) surgery for the correction of refractive errors (IPG164). NICE; 2006. https://www.nice.org.uk/guidance/ipg164 Accessed 5 November 2026.
- American Academy of Ophthalmology (AAO). LASIK — Laser Eye Surgery. AAO; 2026. https://www.aao.org/eye-health/treatments/lasik Accessed 5 November 2026.
- American Academy of Ophthalmology (AAO). What Is Small Incision Lenticule Extraction (SMILE)? AAO; 2026. https://www.aao.org/eye-health/treatments/what-is-small-incision-lenticule-extraction Accessed 5 November 2026.
- US Food and Drug Administration (FDA). What are the risks and how can I find the right doctor for me? FDA. https://www.fda.gov/medical-devices/lasik/what-are-risks-and-how-can-i-find-right-doctor-me Accessed 5 November 2026.
- US Food and Drug Administration (FDA). When is LASIK not for me? FDA. https://www.fda.gov/medical-devices/lasik/when-lasik-not-me Accessed 5 November 2026.
- Shortt AJ, Allan BDS, Evans JR. Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia. Cochrane Database of Systematic Reviews; 2013. https://doi.org/10.1002/14651858.CD005135.pub3 Accessed 5 November 2026.
- Shen Z, Zhu Y, Song X, Yan J, Yao K. Dry eye after small incision lenticule extraction (SMILE) versus femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia: a meta-analysis. PLoS ONE; 2016;11(12):e0168081. https://doi.org/10.1371/journal.pone.0168081 Accessed 5 November 2026.
- The Royal College of Ophthalmologists (RCOphth). New Refractive Surgery Standards and patient information improve quality of care and help patients make informed choices. RCOphth; 2017. https://curriculum.rcophth.ac.uk/?p=15708 Accessed 5 November 2026.
Article history
- — First published.