What is the difference between LASIK and SMILE?

Both LASIK and SMILE use a femtosecond laser to reshape the cornea, but they differ in technique. LASIK creates a thin hinged flap, lifts it, uses an excimer laser to reshape the tissue beneath, then replaces the flap. SMILE is flapless — a small lenticule of tissue is cut entirely within the cornea and removed through a tiny keyhole incision. Because there is no flap, SMILE avoids flap-related complications and preserves more corneal surface nerves, which may reduce dry eye symptoms. Visual recovery with SMILE is slightly slower than LASIK but typically faster than PRK.

Am I a suitable candidate for laser vision correction?

Suitable candidates typically have a stable glasses prescription for at least two years, sufficient corneal thickness, no significant corneal disease such as keratoconus, are aged 18 or older, and have acceptable tear film function. Corneal topography and tomography are essential before any laser procedure to screen for subtle irregularities. Some patients who are not suitable for LASIK or SMILE — due to thin corneas or high prescriptions — may be candidates for PRK or refractive lens exchange instead.

Is laser vision correction permanent?

Laser procedures permanently reshape the cornea to correct your prescription at the time of surgery. For most patients the result is long-lasting. However, the eye can still change over time — particularly with the onset of presbyopia (age-related reading vision loss) in your 40s — and a small proportion of patients experience some prescription regression and may benefit from an enhancement procedure. Age-related conditions such as cataracts also continue to develop regardless of prior laser surgery.

What is refractive lens exchange (RLE)?

Refractive lens exchange — also called clear lens extraction — is a procedure in which the natural lens of the eye is removed and replaced with an artificial intraocular lens (IOL) selected to correct your prescription. It uses the same technique as cataract surgery, but is performed on a clear lens before a cataract has formed. RLE is particularly suited to patients over 45 with high prescriptions that fall outside the safe range for laser correction, those with early lens changes, or those who wish to address both distance and reading vision simultaneously.

Can refractive lens exchange correct presbyopia?

Yes. Because RLE removes the natural lens — which progressively loses its flexibility from the mid-40s onwards — and replaces it with a premium IOL, the procedure can address presbyopia at the same time as correcting distance and intermediate vision. Extended depth of focus (EDOF) lenses and multifocal IOLs are designed specifically to provide a range of clear vision and reduce or eliminate dependence on reading glasses after surgery.

What is the difference between laser surgery and RLE for patients over 45?

Laser surgery (LASIK, PRK, SMILE) reshapes the cornea and corrects your distance prescription, but does not affect the lens — so presbyopia continues to progress after surgery, and reading glasses are still typically needed. RLE replaces the natural lens entirely, correcting both your prescription and — with the right IOL — presbyopia at the same time. RLE also permanently eliminates the future risk of cataracts. The right choice depends on corneal thickness, prescription, lifestyle, and visual goals, and should be discussed in detail at a pre-operative consultation.

Services

Refractive Surgery Melbourne

Refractive surgery encompasses a range of procedures designed to reduce or eliminate dependence on glasses and contact lenses by correcting the optical errors of the eye. Options include corneal laser procedures — LASIK, PRK, and SMILE — and refractive lens exchange, in which the natural lens is replaced with a premium intraocular implant.

Dr Ross MacIntyre MD FRANZCO completed fellowship training in cornea, complex cataract, and refractive surgery at the Wilmer Eye Institute at Johns Hopkins Hospital. He consults at Northern Eye Consultants at Northpark Private Hospital in Bundoora.

What Is Refractive Surgery?

The eye focuses light using two main structures: the cornea (the clear front surface of the eye) and the natural lens (which sits behind the iris). When the shape of the eye does not focus light precisely on the retina, the result is a refractive error — myopia (short-sightedness), hyperopia (long-sightedness), or astigmatism — that is corrected by glasses or contact lenses.

Refractive surgery aims to correct these errors permanently. Corneal laser procedures — LASIK, PRK, and SMILE — reshape the cornea using precise laser energy to alter how it focuses light. Refractive lens exchange (RLE) takes a different approach: the natural lens is replaced with an artificial implant chosen to correct the prescription, including for patients whose prescriptions fall outside the safe range for laser treatment or who are developing presbyopia.

Selecting the right procedure requires a thorough pre-operative assessment. Corneal thickness, shape, prescription, age, tear film quality, and lifestyle all influence which option is most appropriate for a given patient.

LASIK (Laser In-Situ Keratomileusis)

LASIK is the most widely performed elective surgical procedure in the world. A femtosecond laser creates a thin hinged flap in the outer cornea — typically around 100 microns thick. The flap is lifted, and an excimer laser precisely removes microscopic amounts of corneal tissue from the underlying stroma to reshape the cornea according to your prescription. The flap is then repositioned and adheres without stitches.

Visual recovery is rapid. Most patients notice significant improvement within 24–48 hours, and vision typically stabilises within one to two weeks. Discomfort is minimal — usually a mild foreign body sensation for the first few hours.

Candidacy for LASIK

Stable prescription for at least two years
Sufficient corneal thickness (usually >500 microns) to leave an adequate residual bed after treatment
Normal corneal shape — no evidence of keratoconus or forme fruste keratoconus on topography
No significant dry eye
Age 18 or older
Prescription within treatable range (typically up to approximately −10 D myopia, +4 D hyperopia, 5 D astigmatism)

Because a flap is created and lifted, patients in high-contact sports or occupations with a risk of eye trauma may prefer a flapless procedure such as PRK or SMILE.

PRK (Photorefractive Keratectomy)

PRK was the original form of corneal laser surgery and continues to be an excellent choice for many patients. Instead of creating a flap, PRK removes the thin surface layer of epithelial cells from the cornea, allowing the excimer laser to reshape the tissue directly on the surface. The epithelium regrows naturally over three to five days beneath a soft contact lens placed at surgery.

Visual recovery with PRK is slower than LASIK — most patients achieve functional vision within one to two weeks, with further refinement over the following weeks as healing progresses. However, because there is no flap, there is no risk of flap-related complications, and more of the corneal thickness is preserved — an important consideration for patients with thinner corneas.

When PRK is Preferred

Corneas that are thinner or have less residual thickness after the planned treatment
Patients engaged in contact sports, martial arts, or occupations with eye trauma risk (military, police, emergency services)
History of corneal surface disease
Patients concerned about flap-related complications
Aviation applicants where PRK is approved and LASIK may be restricted
Mild dry eye where preserving more corneal surface nerves is advantageous

SMILE (Small Incision Lenticule Extraction)

SMILE is the newest corneal laser procedure and is entirely flapless. A single femtosecond laser creates a disc-shaped piece of tissue (a lenticule) entirely within the cornea, then extracts it through a small 2–4 mm arc-shaped incision. Because the lenticule is removed, the corneal shape changes in a way that corrects the prescription — without ever creating a flap and without using an excimer laser.

The key advantage of SMILE is its minimally invasive, flapless approach. The small incision preserves far more of the anterior corneal nerve fibres compared with LASIK, which may translate to fewer dry eye symptoms in the post-operative period. There is also no flap to displace in the event of eye trauma. Visual recovery is typically faster than PRK but slightly slower than LASIK — most patients are functional within a few days.

SMILE Candidacy

SMILE is currently approved for myopia and myopic astigmatism. Candidacy requirements regarding corneal thickness and topography are similar to LASIK. Patients with dry eye who want a laser procedure, and patients who prefer a flapless approach for lifestyle or occupational reasons, are often good candidates for SMILE.

Refractive Lens Exchange (RLE)

Refractive lens exchange (also called clear lens extraction) uses the same surgical technique as cataract surgery: the natural lens of the eye is removed through a 2–3 mm micro-incision and replaced with an artificial intraocular lens (IOL) calculated to correct the prescription. The difference is that in RLE the lens being removed is optically clear — no cataract has yet formed.

RLE is a permanent procedure. Because the natural lens is removed, it cannot develop a cataract in the future — eliminating the need for a separate cataract operation later in life. The artificial lens implant does not degrade or wear out.

Who Is RLE Suited To?

RLE is particularly well suited to:

Patients over 45 experiencing presbyopia (difficulty with near vision) who wish to address both distance and reading vision
High myopes (typically above −10 D) or high hyperopes whose prescriptions are outside the safe range for laser correction
Patients with thinner corneas that would leave insufficient residual tissue after laser ablation
Patients with early lens changes who are likely to need cataract surgery within the next few years
Patients who want permanent elimination of future cataract risk

IOL Options for RLE

The intraocular lens chosen for RLE determines the range of vision achieved after surgery. There are four main categories, each with specific advantages:

Monofocal IOL

Corrects vision at one distance — typically set for distance. Reading glasses are still required for near tasks. Covered by Medicare for cataract surgery; for RLE these are a patient-funded cost.

Toric IOL

A monofocal lens that also corrects astigmatism. Suitable for patients with significant corneal astigmatism who want good unaided distance vision.

EDOF Lens (Extended Depth of Focus)

Provides clear distance and intermediate vision (computer screens, dashboard) with reduced — but often not eliminated — need for reading glasses. Produces fewer halos and starbursts than multifocal lenses.

Multifocal IOL

Uses multiple focal zones to provide distance, intermediate, and near vision simultaneously, offering the highest level of spectacle independence. Trade-offs include halos, starbursts, and reduced contrast sensitivity — particularly at night. Suits motivated patients with appropriate expectations.

For further reading on lens options, see the pages on monofocal IOLs, toric IOLs, EDOF lenses, and multifocal IOLs. Dr MacIntyre has also written in detail about refractive lens exchange for patients over 45.

How to Choose the Right Procedure

The decision between laser surgery and lens-based surgery — and between the different laser options — depends on several factors assessed during a pre-operative consultation. Here is a general framework:

Age and presbyopia

Patients under 40 without presbyopia are generally good candidates for laser procedures (LASIK, PRK, SMILE) if their corneas and prescriptions are suitable. Patients over 45 with presbyopia may prefer RLE, which can correct both distance and reading vision simultaneously through the choice of a premium IOL.

Prescription

Most laser procedures are effective for myopia up to approximately −10 D, hyperopia to +4 D, and astigmatism to around 5 D. Higher prescriptions, particularly high hyperopia, are generally better addressed with RLE. Very high myopes may also achieve better outcomes with a lens-based approach.

Corneal thickness and shape

Laser procedures require adequate corneal thickness to perform the ablation and still leave a safe residual stromal bed. Patients with thinner corneas, or those with subtle corneal irregularity on topography, may be steered toward PRK (which conserves more tissue than LASIK) or to RLE. Corneal tomography is essential in every pre-operative assessment to screen for keratoconus.

Lifestyle and occupation

LASIK offers the fastest recovery and suits most lifestyle situations. SMILE or PRK are preferred for contact sport athletes or occupations with eye trauma risk. RLE involves a slightly longer post-operative period similar to cataract surgery.

Dry eye

Pre-existing dry eye is evaluated carefully before any laser procedure. SMILE preserves more corneal surface nerves than LASIK and may cause less post-operative dry eye. Severe dry eye may make lens-based surgery the safer choice.

Subspecialty Training in Refractive Surgery

Dr Ross MacIntyre MD FRANZCO completed subspecialty fellowship training in cornea, complex cataract, and refractive surgery at the Wilmer Eye Institute at Johns Hopkins Hospital in Baltimore — refractive surgery being one of the three named specialties of his fellowship. The Wilmer Eye Institute is among the world's most recognised academic ophthalmology centres and handles a high volume and complexity of refractive cases, including lens-based surgery for patients with complex prescriptions and corneal pathology.

Prior to his Johns Hopkins training, Dr MacIntyre completed his ophthalmology residency at Brown University in Providence, Rhode Island — one of the eight Ivy League universities — where he was appointed Chief Resident. He subsequently completed a cornea fellowship at the Royal Victorian Eye and Ear Hospital in Melbourne and holds a Staff Specialist appointment there. Full details of his training background are available at drmacintyre.com.

Fellowship: Wilmer Eye Institute, Johns Hopkins Hospital — cornea, complex cataract, and refractive surgery
Residency: Brown University (Ivy League), Providence, Rhode Island — appointed Chief Resident
FRANZCO — highest specialist qualification in ophthalmology in Australia and New Zealand
Staff Specialist, Royal Victorian Eye and Ear Hospital
Experience with complex refractive cases including lens-based correction for high prescriptions and combined procedures
Consulting at Northern Eye Consultants, Northpark Private Hospital, Bundoora

FAQ

Refractive Surgery — Frequently Asked Questions

Considering Refractive Surgery?

A thorough pre-operative assessment is essential before any refractive procedure. A referral from your GP or optometrist is required to see Dr MacIntyre. Once you have a referral, appointments can be booked through Northern Eye Consultants.

Book via Northern Eye Consultants