LASIK vs SMILE: Which Laser Vision Correction Procedure Is Better?

Author: Dr Val Phua
Estimated reading time: 17 minutes

LASIK and SMILE are two established forms of laser vision correction used to reduce dependence on spectacles and contact lenses.

Both procedures permanently reshape the cornea so that light focuses more accurately on the retina. In appropriately selected patients, both can provide excellent unaided vision, high refractive accuracy and long-term stability.

The principal difference is how the corneal tissue is treated:

LASIK creates a thin corneal flap. An excimer laser then reshapes the underlying corneal tissue.
SMILE uses a femtosecond laser to create a small lens-shaped piece of tissue—called a lenticule—within the cornea. The surgeon removes this lenticule through a small incision without creating a LASIK-style flap.

Comparative studies generally find that LASIK and SMILE produce similar final visual acuity, safety and refractive accuracy for myopia and myopic astigmatism. The choice usually depends on the patient’s corneal anatomy, prescription, dry-eye status, occupation, sporting activities, treatment customisation needs and tolerance for the different risks of each procedure. [1–5]

LASIK vs SMILE at a Glance

LASIK May Be Favoured When:

Very rapid initial visual recovery is a priority
Wavefront-guided or topography-guided treatment is desirable
Hyperopia or mixed astigmatism requires correction
A future enhancement may be more likely
The surgeon wants direct access to the treatment bed
The cornea and tear film are suitable for flap-based treatment

SMILE May Be Favoured When:

Avoiding a corneal flap is important
The patient participates in contact or impact sports
Dry-eye risk is a major concern
Preserving more anterior corneal nerves is desirable
Myopia with or without regular astigmatism is being treated
The patient’s corneal anatomy and prescription fit the available treatment range

Neither list replaces a comprehensive refractive assessment.

What Is LASIK?

LASIK stands for Laser-Assisted In Situ Keratomileusis.

Modern femtosecond LASIK generally uses two lasers:

A femtosecond laser creates a thin, hinged corneal flap.
The surgeon lifts the flap.
An excimer laser removes microscopic amounts of tissue from the underlying corneal stroma.
The flap is repositioned over the treated area.

The excimer laser reshapes the cornea by removing tissue according to the patient’s prescription and treatment plan.

For myopia, the central cornea is flattened. For hyperopia, the mid-peripheral cornea is reshaped to make the centre relatively steeper. Astigmatism is treated by applying different amounts of correction across different meridians. [6]

What Is Bladeless or Femto-LASIK?

Bladeless LASIK means that the corneal flap is created with a femtosecond laser rather than a mechanical microkeratome blade.

The second stage still uses an excimer laser to reshape the cornea.

Femtosecond-laser flap creation allows the surgeon to plan:

Flap diameter
Flap thickness
Hinge position
Side-cut angle
Flap shape

Most modern LASIK procedures are performed using femtosecond-laser flap creation.

What Is SMILE?

SMILE stands for Small-Incision Lenticule Extraction.

The procedure uses a femtosecond laser to create:

A thin, lens-shaped lenticule inside the cornea
A small access incision at the surface of the cornea

The surgeon separates and removes the lenticule through the incision.

Removing this tissue changes the shape of the cornea and corrects the myopia and astigmatism.

Unlike LASIK:

No broad corneal flap is created
No excimer laser ablation is performed
The central anterior corneal surface remains largely intact apart from the small incision

The United States FDA-approved SMILE indication includes myopia from −1.00 to −10.00 D, with astigmatism from −0.75 to −3.00 D, in adults aged 22 years or older with a stable prescription. Regulatory indications and available treatment ranges may differ in Singapore and other countries. [7,8]

What Is a Corneal Lenticule?

A lenticule is a precisely shaped piece of corneal stromal tissue.

Its:

Thickness
Diameter
Shape
Astigmatic orientation

are determined by the intended refractive correction.

For myopia, the lenticule is thicker centrally. Removing it flattens the central cornea and reduces its focusing power.

The tissue removal is permanent. SMILE should therefore not be described as reversible. [7]

What Is the Main Difference Between LASIK and SMILE?

The main structural difference is the corneal access method.

LASIK

Creates a broad hinged flap
Uses an excimer laser beneath the flap
Provides direct access to the stromal treatment bed
Allows wavefront- or topography-guided excimer treatment on appropriate platforms
Leaves a permanent flap interface

SMILE

Creates an internal lenticule
Removes the lenticule through a small incision
Avoids a LASIK-style flap
Uses only the femtosecond laser for the refractive treatment
Leaves a cap and internal interface rather than a hinged flap

Both procedures permanently remove corneal tissue.

Which Gives Better Vision: LASIK or SMILE?

For appropriately selected patients with myopia or myopic astigmatism, final visual outcomes are generally similar.

Comparative studies and meta-analyses have found broadly comparable:

Unaided distance visual acuity
Best-corrected visual acuity
Refractive predictability
Safety
Astigmatism correction
Patient satisfaction

A 2024 paired-eye study found similar unaided and corrected vision between SMILE and femtosecond LASIK at up to one year. A separate three-year comparison concluded that both were safe and similarly effective for myopia and astigmatism. [1,4]

The result depends more on:

Patient selection
Accuracy of the refraction
Corneal measurements
Treatment centration
Optical-zone planning
Laser platform
Surgical technique
Postoperative healing

than on the procedure name alone.

Which Has Faster Visual Recovery?

LASIK generally provides faster initial visual recovery.

Many LASIK patients see substantially better within several hours and have functional vision by the following day.

SMILE recovery is also relatively quick, but vision may take slightly longer to become crisp. Some patients notice:

Mild haziness
Fluctuating vision
Reduced contrast
A difference between the two eyes
Slower recovery of very fine detail

during the first few days.

A prospective randomised contralateral-eye study found that wavefront-guided LASIK provided faster visual recovery and better early low-contrast visual acuity than SMILE. Reviews have similarly found that early visual recovery may be slower after SMILE, although final results generally become comparable. [9,10]

Typical Functional Recovery

Many patients can return to office-based activities:

Within one or two days after LASIK
Within a few days after SMILE

Individual recovery varies. Driving should resume only when vision is legally adequate and the surgeon has confirmed that it is safe.

Is LASIK More Painful Than SMILE?

Both procedures are performed using anaesthetic eyedrops and should not cause sharp pain during surgery.

Patients may feel:

Pressure
Tightness
Bright lights
Water around the eye
Temporary loss or dimming of vision during laser docking

After LASIK, tearing, burning and light sensitivity may be most noticeable during the first several hours.

After SMILE, mild grittiness, watering or light sensitivity may occur. Some patients experience slightly more prolonged visual haze even when discomfort is mild.

Severe or increasing pain is not considered a normal feature of either recovery.

Which Procedure Causes Less Dry Eye?

SMILE generally causes less disruption to the anterior corneal nerves and may produce less early postoperative dry eye than LASIK.

The corneal nerves help regulate:

Tear production
Blinking
Corneal sensation
Eye-surface healing

Creating a broad LASIK flap cuts more of the superficial corneal nerve network. SMILE uses a smaller incision and preserves more of the anterior corneal surface.

A 2025 meta-analysis of 18 studies found better tear-film stability and some tear-production measurements after lenticule extraction compared with femtosecond LASIK. Earlier meta-analyses also found faster corneal-sensitivity recovery and fewer early dry-eye symptoms after SMILE. [2,11,12]

However:

SMILE can still cause dry eye
LASIK dry eye is often temporary
Differences may become smaller over time
Pre-existing meibomian gland dysfunction may be more important than the procedure itself
Severe dry eye can make either procedure unsuitable

Dry-eye disease, blepharitis and eyelid-gland dysfunction should be treated before surgery.

Does SMILE Completely Avoid Corneal-Nerve Damage?

No.

The SMILE laser still creates:

An anterior cap interface
A posterior lenticule interface
A small incision
Disruption of stromal nerves within the treated area

The difference is one of degree and distribution rather than complete nerve preservation.

Corneal sensation generally recovers after either procedure, but recovery may occur earlier after SMILE.

What Is the LASIK Flap?

The LASIK flap is a thin layer of corneal tissue that remains attached by a hinge.

Once repositioned, the flap adheres without stitches.

The surface epithelium seals relatively quickly, but the deeper flap interface does not regain the same tensile strength as untouched corneal tissue.

This creates several LASIK-specific considerations:

Flap displacement
Flap folds or striae
Epithelial ingrowth
Interface inflammation
Diffuse lamellar keratitis
Trauma-related flap movement

These complications are uncommon with modern femtosecond LASIK but are not possible in exactly the same form after flap-free SMILE.

Can a LASIK Flap Move Years Later?

Significant late movement is uncommon, but severe trauma can disturb a LASIK flap even years after surgery.

Risk is most relevant for people exposed to:

Direct blows to the eye
Fingernail injuries
Martial arts
Boxing
Contact sports
Military or tactical activities
Occupations involving facial trauma

Most LASIK patients resume normal activities without flap problems. Nevertheless, patients with a high lifetime risk of direct eye trauma may prefer SMILE or a surface-ablation procedure.

Is SMILE Better for Contact Sports?

SMILE may be attractive for contact-sport athletes because there is no broad corneal flap to displace.

Potentially relevant activities include:

Martial arts
Boxing
Rugby
Football
Basketball
Water polo
Military training
Law-enforcement work

However, SMILE does not make the eye immune to injury. Trauma can still cause:

Corneal abrasions
Inflammation
Retinal tears
Retinal detachment
Other internal eye injuries

Protective eyewear remains advisable whenever practical.

Which Procedure Preserves More Corneal Strength?

SMILE is designed to preserve more of the anterior stromal architecture because it avoids a broad flap.

The anterior corneal stromal fibres are considered to contribute significantly to corneal strength. In LASIK, these fibres are cut during flap creation and do not contribute fully to the load-bearing residual stromal bed.

In SMILE, most of the anterior surface remains continuous apart from the small incision.

Biomechanical models therefore suggest that SMILE may preserve more corneal strength for an equivalent correction.

However, the clinical difference is complex and should not be overstated.

Corneal strength after either procedure depends on:

Preoperative corneal shape
Corneal thickness
Treatment depth
Optical-zone diameter
Cap or flap thickness
Prescription
Residual stromal tissue
Undetected keratoconus susceptibility
Individual wound healing

Can Corneal Ectasia Occur After LASIK or SMILE?

Yes.

Corneal ectasia is progressive weakening and bulging of the cornea after refractive surgery.

It may cause:

Increasing myopia
Increasing irregular astigmatism
Ghosting
Reduced best-corrected vision
Difficulty wearing standard spectacles
Need for rigid or scleral contact lenses
Need for corneal cross-linking

A systematic review found reported post-refractive ectasia after LASIK, PRK and SMILE. The reported incidence appeared lower after SMILE than after LASIK, but the authors cautioned that SMILE had a shorter history, fewer total procedures and incomplete case reporting. The presence of pre-existing or forme-fruste keratoconus remained an important factor. [13]

No procedure eliminates ectasia risk.

The most important protection is careful preoperative screening.

Is SMILE Always Safer for a Thin Cornea?

No.

Although SMILE avoids a LASIK flap, it still removes corneal stromal tissue.

Suitability depends on:

Total corneal thickness
Cap thickness
Lenticule thickness
Residual stromal thickness
Corneal tomography
Epithelial thickness mapping
Biomechanical assessment
Degree of correction

A thin or suspicious cornea may be unsuitable for both LASIK and SMILE.

Alternative options may include:

PRK or surface ablation
ICL surgery
Spectacles
Contact lenses
No surgery

Which Procedure Can Treat a Wider Range of Prescriptions?

LASIK generally offers greater treatment flexibility.

Depending on the laser platform and local approval, LASIK can treat:

Myopia
Hyperopia
Myopic astigmatism
Hyperopic astigmatism
Mixed astigmatism
Monovision targets

The FDA-approved MEL 90 LASIK indication includes myopia, hyperopia and mixed astigmatism within specified ranges. [6]

SMILE is primarily used for:

Myopia
Myopic astigmatism

Under current United States FDA labelling, SMILE is approved for myopia from −1.00 to −10.00 D and cylinder from −0.75 to −3.00 D. Local approved ranges may differ. [7,8]

Can SMILE Treat Hyperopia?

Hyperopic lenticule extraction is being studied and may be available in limited settings or under different regulatory frameworks.

However, SMILE remains predominantly established and approved for myopia with or without astigmatism.

LASIK currently has a more established role for hyperopia and mixed astigmatism.

Which Procedure Is Better for High Myopia?

Both LASIK and SMILE may correct high myopia when the cornea is sufficiently thick, regular and structurally suitable.

As the intended myopic correction increases:

More corneal tissue must be removed
The residual stromal tissue becomes thinner
Regression may become more likely
Optical-zone planning becomes more challenging
Night-vision symptoms may become more relevant
Ectasia risk must be assessed carefully

SMILE has shown stable outcomes in many moderate- and high-myopia studies, including follow-up extending to five, seven and ten years. However, some long-term studies found greater regression or less predictable remodelling in higher-myopia groups. [14–18]

LASIK also has extensive long-term evidence, but high corrections can show refractive regression and may require enhancement.

For very high myopia, thin corneas or borderline tissue calculations, an ICL may provide a safer alternative because it corrects the prescription without removing central corneal tissue.

Which Procedure Corrects Astigmatism Better?

Both procedures can effectively correct regular myopic astigmatism.

The result depends on:

Accuracy of the measured cylinder
Axis consistency
Treatment centration
Cyclotorsion
Corneal healing
Laser platform
Degree of astigmatism

LASIK platforms may offer:

Iris registration
Cyclotorsion compensation
Wavefront-guided correction
Topography-guided correction

SMILE requires accurate docking, centration and lenticule orientation. Newer systems may provide digital alignment assistance, but available features vary by platform and market.

Comparative studies generally show similar overall cylinder correction, although results may differ in specific groups such as high or oblique astigmatism. [1,4,19]

What Is Wavefront-Guided LASIK?

Wavefront-guided LASIK uses measurements of the eye’s optical aberrations to create a customised excimer-laser treatment.

The aim is to correct the spectacle prescription while reducing the induction of additional higher-order aberrations.

It may be useful when:

Preoperative wavefront measurements are reliable
The optical system shows particular aberration patterns
Night vision and low-contrast performance are priorities
The pupil and treatment zone are appropriately planned

A randomised contralateral-eye study found faster early visual recovery and better low-contrast performance with wavefront-guided LASIK than SMILE, although both procedures provided marked visual improvement. [9]

What Is Topography-Guided LASIK?

Topography-guided LASIK uses detailed corneal surface measurements to plan treatment.

It may help address:

Corneal asymmetry
Decentration
Certain regular optical irregularities
Corneal higher-order aberrations

Topography-guided treatment is not appropriate for every irregular cornea and should not be used to conceal progressive keratoconus.

LASIK currently provides broader established options for wavefront- or topography-guided customisation than standard SMILE.

Is SMILE Less Accurate Because It Is Not Wavefront-Guided?

Not necessarily.

Standard prescriptions can be corrected very accurately using either procedure.

Most comparative studies find similar final visual acuity and refractive predictability.

Customisation becomes more relevant when a patient has:

Significant corneal asymmetry
Large pupils
Previous refractive surgery
Significant higher-order aberrations
Unusual visual-quality complaints

In such cases, a customised LASIK or surface-ablation strategy may offer planning options that conventional SMILE does not.

Which Procedure Has Better Night Vision?

Most patients have satisfactory night vision after either procedure.

Both can temporarily or persistently cause:

Glare
Halos
Starbursts
Ghosting
Reduced contrast sensitivity
Difficulty driving at night

Risk is influenced by:

Pupil size
Optical-zone diameter
Degree of correction
Treatment centration
Residual astigmatism
Dry eye
Higher-order aberrations
Pre-existing night-vision symptoms

The FDA notes that visual symptoms such as glare, halos and double vision can occur after LASIK, even when standard eye-chart vision is good. The SMILE patient booklet similarly states that the procedure is not risk-free and that patients may lose some lines of vision or require further correction. [7,20]

There is no universal rule that LASIK or SMILE always provides better night vision. The treatment plan and individual eye are more important.

Does LASIK Have Better Centration?

LASIK excimer-laser systems may include active eye tracking and iris-registration technology.

These systems can compensate for:

Small eye movements
Cyclotorsion
Pupil-centre shifts
Differences between upright and lying positions

SMILE involves docking the eye to the femtosecond laser. Accurate initial centration is therefore important because the lenticule pattern is created during docking.

Experienced surgeons use:

Visual-axis assessment
Corneal reflexes
Pupil position
Fixation behaviour
Digital guidance where available

Both procedures can be centred accurately, but the mechanisms differ.

Which Procedure Is Easier to Enhance?

LASIK generally offers a more straightforward enhancement pathway.

If a residual prescription remains after LASIK, the surgeon may sometimes:

Relift the existing flap
Apply additional excimer-laser treatment
Perform PRK over the flap
Use spectacles or contact lenses

Flap relifting is not always advisable, particularly many years later, because epithelial ingrowth and other flap-related risks may increase.

Enhancement After SMILE

After SMILE, enhancement options may include:

PRK over the SMILE cap
Converting the SMILE cap into a LASIK-style flap using a specialised laser pattern
Repeat lenticule extraction in selected cases
Spectacles or contact lenses
ICL in selected eyes

A review of PRK enhancement after SMILE reported that enhancement is generally uncommon and that PRK can be effective when a suitable residual prescription remains. [21]

SMILE enhancement is feasible, but it is generally less direct than lifting a recent LASIK flap.

How Often Is an Enhancement Needed?

Enhancement rates vary with:

Preoperative prescription
Age
Laser platform
Treatment nomogram
Healing
Definition of enhancement
Length of follow-up
Surgeon threshold for re-treatment

Higher prescriptions and longer follow-up generally increase the chance of residual or recurrent refractive error.

A small residual prescription does not necessarily mean the operation has failed. It may be managed with spectacles for specific tasks when unaided vision remains satisfactory.

Which Is Better for Someone With Dry Eyes?

SMILE may be preferred when the patient has mild-to-moderate dry-eye risk but otherwise healthy ocular anatomy.

However, the underlying cause of dryness matters.

A patient with:

Severe aqueous-deficient dry eye
Significant meibomian gland dysfunction
Active blepharitis
Exposure keratopathy
Autoimmune-related ocular-surface disease
Corneal staining

may be unsuitable for either procedure until the eye surface is adequately treated.

The FDA SMILE booklet lists severe dry eye as a contraindication. The FDA also warns that LASIK can worsen dry-eye symptoms. [7,20]

Which Is Better for Someone With a Thin Cornea?

Neither procedure can be selected from corneal thickness alone.

The surgeon must consider:

Corneal tomography
Epithelial thickness
Total tissue removal
Flap or cap thickness
Residual stromal tissue
Percentage tissue altered
Biomechanical risk
Prescription

A thin but regular cornea may sometimes be suitable for:

SMILE
Thin-flap LASIK
PRK
ICL

depending on the complete assessment.

A thin cornea with suspicious tomography may be unsuitable for all corneal laser procedures.

Which Is Better for Someone With Keratoconus?

Neither LASIK nor SMILE is appropriate for progressive keratoconus.

Both permanently remove corneal tissue and can worsen structural instability.

Patients with suspected or established keratoconus may require:

Observation
Corneal cross-linking
Specialised contact lenses
Intracorneal ring segments in selected cases
ICL for residual refractive error after the cornea is stable
Other corneal treatment

Even stable or mild keratoconus requires specialist evaluation before any elective refractive procedure.

Can LASIK or SMILE Treat Presbyopia?

Neither procedure restores natural accommodation.

Both may be used in a monovision strategy:

One eye is targeted for distance
The other eye retains mild myopia for near or intermediate vision

Potential disadvantages include:

Reduced depth perception
Reduced stereoacuity
Night-driving difficulty
Eye imbalance
Incomplete near vision

A contact-lens monovision trial is advisable before surgery whenever practical.

Patients corrected fully for distance may require reading glasses as presbyopia develops. Both FDA patient booklets emphasise that laser correction does not eliminate the future need for reading glasses. [6,7]

Are LASIK and SMILE Permanent?

Yes.

Both procedures permanently remove corneal tissue.

They cannot be reversed by replacing the removed tissue.

However, the eye can continue to change because of:

Myopia progression
Presbyopia
Cataract
Corneal remodelling
Hormonal changes
Diabetes-related refractive shifts
Other eye disease

A permanent procedure does not guarantee a permanently unchanged prescription.

What Are the Main Risks of LASIK?

LASIK risks include:

Dry eye
Under- or overcorrection
Residual astigmatism
Glare, halos or ghosting
Flap displacement
Flap folds or striae
Epithelial ingrowth
Diffuse lamellar keratitis
Infection
Interface debris
Corneal ectasia
Loss of best-corrected vision
Need for enhancement
Persistent neuropathic corneal pain in rare cases

The FDA advises that some patients develop significant visual symptoms, reduced low-contrast vision or ongoing dryness despite good standard visual acuity. [20]

What Are the Main Risks of SMILE?

SMILE risks include:

Dry eye
Under- or overcorrection
Residual astigmatism
Glare, halos or ghosting
Suction loss during treatment
Difficult lenticule separation
Retained lenticule tissue
Cap perforation or tear
Interface inflammation
Interface debris
Infection
Corneal ectasia
Decentration
Loss of best-corrected vision
Need for enhancement

The absence of a flap removes flap-specific complications but does not make SMILE risk-free. [7]

What Happens if Suction Is Lost During SMILE?

The eye is docked to the femtosecond laser during lenticule creation.

If suction is lost, management depends on:

How far the laser treatment has progressed
Which cutting plane was being created
The laser platform
The appearance of the tissue planes
Surgeon experience

The procedure may be:

Restarted
Completed with an adjusted plan
Converted to another procedure
Postponed

Suction loss is uncommon with modern systems but remains a recognised SMILE-specific event.

Which Procedure Has More Long-Term Evidence?

LASIK has the longer overall clinical history.

LASIK has been performed widely since the 1990s, and long-term studies extend beyond 20 years for some patients and platforms.

SMILE was introduced later, but published evidence now includes:

Five-year studies
Seven-year studies
Multiple ten-year studies

Ten-year SMILE studies generally support long-term safety and effectiveness, although some refractive regression may occur, particularly after higher corrections. [15–18]

A review of long-term PRK, LASIK and SMILE evidence concluded that all three can provide high long-term safety within suitable treatment ranges, without a clear universal winner. [22]

Does One Procedure Regress More?

Refractive regression can occur after both procedures.

Risk may be influenced by:

High preoperative myopia
Younger age
Ongoing axial elongation
Corneal healing
Optical-zone size
Natural-lens changes
Hormonal or metabolic factors

Some comparative long-term studies have found similar stability, while others have reported slightly more favourable outcomes for one procedure within their particular patient populations.

A seven-year comparative study found good predictability with both SMILE and femtosecond LASIK and reported some refractive advantages for SMILE. These findings do not establish that SMILE will be more stable in every patient. [5]

Who May Be Suitable for Either Procedure?

A typical suitable candidate has:

A stable prescription
Adequate age and refractive maturity
Healthy corneas
Normal or acceptably stable corneal tomography
Adequate corneal thickness
Controlled dry-eye disease
No significant cataract
No active infection or inflammation
Realistic expectations
Willingness to attend follow-up

Who May Not Be Suitable?

LASIK and SMILE may be unsuitable when there is:

Progressive keratoconus
Suspicious corneal tomography
Inadequate residual stromal tissue
Severe dry eye
Active blepharitis or eye-surface inflammation
Active eye infection
Unstable refraction
Pregnancy or breastfeeding
Uncontrolled diabetes
Active autoimmune or connective-tissue disease
Significant cataract
Vision-limiting retinal or optic nerve disease
Unrealistic expectations

The precise contraindications depend on the patient, laser platform and applicable regulatory guidance. [6–8,20]

What Tests Are Required Before LASIK or SMILE?

Refraction and Visual Acuity

The assessment measures:

Myopia or hyperopia
Astigmatism
Best-corrected vision
Prescription stability

Cycloplegic refraction may be used to relax accommodation in selected patients.

Corneal Topography and Tomography

These scans assess:

Corneal shape
Front and back corneal elevation
Pachymetry distribution
Keratoconus risk
Corneal asymmetry
Treatment centration

Corneal Thickness

The surgeon calculates whether enough corneal tissue will remain after treatment.

Epithelial Thickness Mapping

Epithelial mapping may help identify:

Early keratoconus patterns
Corneal irregularity
Contact lens warpage
Localised epithelial compensation

Corneal Biomechanical Assessment

Devices such as dynamic Scheimpflug imaging may provide additional information about deformation behaviour.

No single test can guarantee that ectasia will not occur.

Dry-Eye and Eyelid Assessment

The examination may evaluate:

Tear-film stability
Corneal staining
Tear production
Meibomian glands
Blepharitis
Allergy

Pupil Size

Large pupils may increase the relevance of optical-zone planning and night-vision counselling.

Eye Pressure and Optic Nerve

Glaucoma and ocular hypertension should be identified before elective surgery.

Dilated Retinal Examination

This is particularly important in moderate and high myopia.

Laser vision correction does not remove the retinal risks associated with an elongated eye.

LASIK May Be the Better Choice When:

The patient wants the fastest possible early visual recovery
Hyperopia or mixed astigmatism requires correction
Wavefront-guided treatment is appropriate
Topography-guided treatment is desirable
A straightforward enhancement pathway is important
There is no significant dry-eye or trauma concern
The cornea is suitable for a flap

SMILE May Be the Better Choice When:

Avoiding a flap is a major priority
The patient plays contact sports
Dry-eye risk is a concern
Myopia or myopic astigmatism is within the suitable range
The cornea is suitable for lenticule extraction
A slightly slower early visual recovery is acceptable
Extensive customised excimer treatment is not required

PRK May Be Better Than Both When:

The cornea is unsuitable for a LASIK flap
Surface treatment preserves a safer residual structure
The patient can accept slower recovery
Avoiding both a flap and an internal lenticule interface is preferred
A customised excimer treatment is required

ICL May Be Better Than Both When:

The myopia is very high
Corneal tissue is insufficient
Corneal tomography is unsuitable for laser correction
Preserving central corneal tissue is important
The internal eye anatomy is suitable for an implant

ICL introduces intraocular risks and requires different long-term monitoring.

Frequently Asked Questions About LASIK vs SMILE

Is SMILE Safer Than LASIK?

SMILE avoids flap-specific complications and may cause less early dry eye.

LASIK provides faster early recovery and broader customisation.

Both have uncommon but potentially serious risks, including infection, ectasia and loss of best-corrected vision.

Which Procedure Gives Sharper Vision?

Final eye-chart vision is generally similar.

Wavefront-guided or topography-guided LASIK may provide advantages for selected optical profiles, while many standard myopic patients achieve equally sharp functional vision with SMILE.

Which Has Faster Recovery?

LASIK usually provides faster initial recovery.

SMILE vision may take several additional days to become fully crisp.

Which Causes Less Dry Eye?

SMILE generally causes less early corneal denervation and may produce less early postoperative dryness.

Neither procedure eliminates dry-eye risk.

Which Is Better for Contact Sports?

SMILE is often favoured because it avoids a corneal flap.

Which Is Better for High Myopia?

Either may be suitable when the cornea is sufficiently healthy and thick.

ICL should also be considered when a high correction would require excessive corneal tissue removal.

Which Is Better for Astigmatism?

Both can correct regular myopic astigmatism.

LASIK provides broader customisation options on certain platforms.

Can SMILE Correct Long-Sightedness?

SMILE remains primarily established for myopia and myopic astigmatism.

LASIK has a more established role for hyperopia.

Is SMILE Flapless?

Yes, in the sense that it does not create a hinged LASIK flap.

It still creates an anterior corneal cap, internal tissue planes and a small surface incision.

Is SMILE Reversible?

No.

The removed corneal lenticule cannot simply be replaced.

Is LASIK Reversible?

No.

The excimer laser permanently removes corneal tissue.

Can the LASIK Flap Heal Completely?

The flap seals and becomes stable for normal life, but the deeper interface does not regain the strength of untouched corneal tissue.

Can I Rub My Eyes After Surgery?

Eye rubbing should be avoided during early recovery after either procedure.

Habitual vigorous rubbing should also be avoided long term because it may contribute to corneal deformation in susceptible eyes.

Can LASIK or SMILE Cause Blindness?

Severe permanent visual loss is rare but possible.

Potential causes include:

Infection
Severe corneal ectasia
Scarring
Irregular astigmatism
Other uncommon complications

Can I Still Need Glasses?

Yes.

Glasses may still be required for:

A residual prescription
Night driving
Reading after presbyopia develops
Future refractive changes

Which Procedure Is Easier to Enhance?

LASIK generally has a more straightforward enhancement pathway.

SMILE enhancement may involve PRK, cap-to-flap conversion or another technique.

Can I Have LASIK After SMILE?

Potentially.

A SMILE cap can sometimes be converted into a flap, or PRK may be performed over the cornea.

Suitability depends on tissue thickness, anatomy and the residual prescription.

Can I Have SMILE After LASIK?

SMILE is generally not the routine enhancement procedure after LASIK because the existing flap changes the corneal anatomy.

Other enhancement strategies are usually considered.

Does Either Procedure Prevent Presbyopia?

No.

Reading glasses may still be required with age.

Do I Still Need Eye Examinations After Surgery?

Yes.

Regular examinations remain important for:

Eye pressure
Glaucoma
Cataract
Corneal health
Retinal health
Myopia-related complications

Key Takeaway

LASIK and SMILE are both effective forms of laser vision correction.

In most appropriately selected myopic patients, they provide similar final:

Unaided vision
Refractive accuracy
Safety
Patient satisfaction

LASIK generally offers:

Faster early visual recovery
Broader treatment of myopia, hyperopia and mixed astigmatism
Greater wavefront- and topography-guided customisation
A more straightforward enhancement pathway

SMILE generally offers:

No hinged corneal flap
Less early corneal-nerve disruption
Potentially fewer early dry-eye symptoms
Advantages for patients exposed to contact or impact sports
Good long-term stability for myopia and myopic astigmatism

Neither procedure is universally better.

LASIK may be preferred when rapid recovery, customised optical treatment, hyperopia correction or easier enhancement is important.

SMILE may be preferred when avoiding a flap and reducing early eye-surface disruption are priorities.

Both procedures:

Permanently remove corneal tissue
Can cause glare, halos or residual prescription
Carry a small risk of corneal ectasia
Do not prevent presbyopia
Do not eliminate the retinal risks of high myopia
Require careful preoperative screening

The safest procedure is the one that best matches the patient’s prescription, corneal anatomy, tear-film health, lifestyle and long-term visual priorities.

References

Zhang Y, et al. Clinical Outcomes of SMILE and Femtosecond LASIK Used to Treat Myopia: A Meta-analysis. 2016. PMID: 27070233.
Chen KY, et al. Effectiveness of Keratorefractive Lenticule Extraction Compared With Femtosecond LASIK for Dry Eye: A Meta-analysis. 2025. PMID: 40778870.
Ramirez-Miranda A, et al. Visual and Refractive Outcomes After SMILE Versus Femtosecond LASIK: A Paired-Eye Study. 2024. PMID: 39591576.
Han T, et al. Three-Year Outcomes of SMILE and Femtosecond LASIK for Myopia and Astigmatism. 2019. PMID: 30061116.
Zhang L, et al. Seven-Year Refractive Outcomes Comparing SMILE and Femtosecond LASIK. 2024. PMID: 39373787.
US Food and Drug Administration. ZEISS MEL 90 LASIK Patient Information Booklet. 2024.
US Food and Drug Administration. ZEISS VisuMax SMILE Patient Information Booklet.
US Food and Drug Administration. VisuMax Femtosecond Laser SMILE Premarket Approval and Indications for Use.
Chiang B, et al. Prospective Randomised Contralateral-Eye Comparison of Wavefront-Guided LASIK and SMILE. 2022. PMID: 34788593.
Lau YTY, et al. Comparison of Visual, Refractive and Ocular-Surface Outcomes Between SMILE and LASIK. 2019. PMID: 31325106.
Wong AHY, et al. Dry Eyes After SMILE. 2019. PMID: 31490199.
Zhang Y, et al. Corneal Sensitivity and Dry-Eye Outcomes After SMILE and Femtosecond LASIK. 2016. PMID: 27070233.
Moshirfar M, et al. Ectasia After Corneal Refractive Surgery: A Systematic Review. 2021. PMID: 34417707.
Tian M, et al. Five-Year Follow-up of Visual Outcomes and Optical Quality After SMILE. 2021.
Blum M, et al. Ten-Year Results of Small-Incision Lenticule Extraction. 2019. PMID: 31610002.
Damgaard IB, et al. Seven-Year Results of SMILE for High Myopia. 2021. PMID: 34661473.
Pedersen IB, et al. Ten-Year Outcomes Following SMILE for Myopia Up to −10 Dioptres. 2023. PMID: 37194118.
Zhao GH, et al. Ten-Year Evaluation of Efficacy, Safety and Predictability After SMILE. 2024. PMID: 39525777.
Liu M, et al. Five-Year Results of SMILE Versus Femtosecond LASIK. 2019. PMID: 30632671.
US Food and Drug Administration. LASIK: Risks, Patient Selection and Postoperative Expectations.
Moshirfar M, et al. Photorefractive Keratectomy Enhancement After SMILE. 2022. PMID: 36119391.
Taneri S, et al. Long-Term Outcomes of PRK, LASIK and SMILE. 2022. PMID: 34241701.