LASIK vs SMILE in Korea: A Complete Decision Guide for International Patients

3 days ago

6 min read

LASIK and SMILE both reshape the cornea to correct myopia, but LASIK creates a hinged corneal flap to access the tissue while SMILE removes a disc of tissue through a small side incision without a flap. The absence of a flap is the central practical difference and drives most of the comparison.

Korea is a significant destination for refractive surgery, with high procedure volumes and competitive pricing. That also means a lot of marketing, much of which presents SMILE as simply newer and therefore better. The honest position is that each has a defensible indication and the right answer depends on your prescription, corneal measurements and lifestyle. See also our guide to what clinical records to request before leaving a Korean clinic, which matters particularly for eye surgery follow-up abroad.

How each procedure works

LASIK. A femtosecond laser or microkeratome creates a thin hinged flap in the outer cornea. The flap is lifted, an excimer laser ablates the underlying stromal tissue to the calculated shape, and the flap is repositioned without sutures. Visual recovery is rapid because the optically critical surface is largely undisturbed.

SMILE. A femtosecond laser carves a lens-shaped disc of tissue, the lenticule, within the intact cornea, and also cuts a small incision of roughly 2 to 4 mm at the edge. The surgeon extracts the lenticule through that incision. No flap is created; the corneal surface remains largely intact apart from the small incision.

PRK and its variants, for completeness, remove the surface epithelium entirely and ablate the surface directly. Recovery is slower and more uncomfortable, but it removes flap concerns and preserves more posterior corneal tissue. It remains relevant for thin corneas and certain occupations.

What the flap difference actually means

Flap complications are eliminated in SMILE. Flap dislocation after trauma, epithelial ingrowth under the flap, and flap striae are LASIK-specific risks. They are uncommon, but the flap remains a permanent structural feature of the eye.
Corneal nerve disruption differs. LASIK's circular flap cut severs more corneal nerves than SMILE's small incision. Corneal nerve density relates to dry eye symptoms, which is the main reason SMILE is often reported to have less post-operative dry eye, particularly in the first six months.
Biomechanical argument. Because SMILE does not cut the anterior stromal lamellae across a wide arc, it is argued to preserve more corneal strength. The clinical significance of this for ectasia risk remains debated in the literature rather than settled.
Contact sports and physical occupations. Patients in martial arts, contact sports, military or emergency services often prefer a flapless procedure for this reason.

Where LASIK retains real advantages

This is where marketing tends to be one-sided.

Hyperopia. SMILE's approved range in most markets covers myopia and myopic astigmatism. Hyperopic correction is generally a LASIK or PRK procedure.
Astigmatism range and cyclotorsion control. LASIK platforms have mature eye-tracking and cyclotorsion compensation. SMILE's handling of astigmatism has improved substantially but LASIK remains the more established option at higher cylinder.
Enhancement. If a touch-up is needed later, a LASIK flap can often be relifted, which is a simpler procedure. Enhancement after SMILE typically requires converting to a surface procedure or creating a flap, which is more involved.
Speed of visual recovery. LASIK patients commonly see functionally well the next morning. SMILE recovery is often slightly slower in the first few days, though the endpoint at one to three months is comparable in most studies.
Cost. LASIK is generally the less expensive of the two in Korean clinics, though the gap varies.

The measurements that actually decide it

Neither procedure is chosen from a brochure. A proper pre-operative workup produces the numbers that determine candidacy.

Refraction, including cycloplegic refraction. The stable, true prescription rather than the one from a quick autorefractor reading.
Corneal thickness (pachymetry). Determines how much tissue can be safely removed and what residual stromal bed remains.
Corneal topography and tomography. Screens for keratoconus and forme fruste keratoconus, the most important contraindication to both procedures.
Pupil size in dim light. Large pupils relative to the treatment zone are associated with night glare and halos.
Tear film assessment. Pre-existing dry eye predicts post-operative dry eye and may favour SMILE or defer surgery entirely.
Prescription stability. Most surgeons require stability over roughly twelve months, and are cautious in patients under about 18 to 21.

If a clinic offers a price and a booking without producing these numbers, the consultation has not happened yet.

What the comparisons leave out: ICL is a third option

Both LASIK and SMILE remove corneal tissue, so both are limited by how thick your cornea is and how high your prescription is. For high myopia, thin corneas, or patients with significant dry eye, an implantable collamer lens - a lens placed inside the eye in front of the natural lens - may be the more appropriate procedure. It is additive rather than subtractive and is reversible in principle.

ICL is a more invasive intraocular procedure with its own risk profile, including cataract and intraocular pressure considerations, and it costs more. But a consultation that presents only LASIK and SMILE to a patient with a high prescription or thin cornea is presenting an incomplete set of options. Ask about it explicitly.

Recovery timelines, realistically

Day 0 to 1. LASIK: functional vision often the next morning, mild discomfort for hours. SMILE: hazier first day, clearing over 24 to 72 hours.
Week 1. Eye drops on a strict schedule, protective eyewear at night, no rubbing, no swimming, no eye makeup.
Weeks 2 to 4. Most patients back to normal activity. Dry eye symptoms are typically at their most noticeable during this period for LASIK.
Months 1 to 3. Refraction stabilises. Night glare and halos, if present, usually diminish.
Months 3 to 6. Dry eye symptoms in the majority of affected patients continue to improve. Persistent symptoms beyond six months are less common but do occur and should be managed actively.

Flying shortly after surgery is generally permitted but cabin air is dry; carry preservative-free lubricating drops and use them frequently.

Planning refractive surgery as a travel patient

The structural weakness of medical travel for eye surgery is follow-up. Refractive procedures require reviews at day 1, week 1, and typically month 1 and month 3.

Allow at least 5 to 7 days in Korea to cover the day 1 and week 1 reviews in person.
Arrange a local ophthalmologist at home for the later reviews before you travel, and confirm they will accept a patient operated abroad.
Request full operative records: the exact procedure, laser platform, treatment parameters, pre-operative topography and pachymetry, and the planned versus achieved correction. A physician managing a later complication needs these.
Confirm the enhancement policy in writing, including whether the clinic covers a touch-up and for how long, and who pays for the return trip.
Do not schedule surgery in the last days of your trip. Leave room for an unexpected extra review.

Frequently asked questions

Is SMILE safer than LASIK?

SMILE eliminates flap-related complications and is associated with less early dry eye in a number of studies. LASIK has a longer track record and broader treatment range. Both have strong safety records in appropriately selected patients. Selection quality matters more than the choice between them.

Which gives better vision?

For myopia within both procedures' ranges, published outcomes at three to twelve months are broadly comparable in terms of uncorrected acuity and predictability. Differences tend to appear in the early recovery period rather than the endpoint.

Will I still need reading glasses?

Yes, eventually. Neither procedure prevents presbyopia, the age-related loss of near focus that typically begins in the mid-forties. Correcting distance vision in a myopic patient can make the onset of reading difficulty more noticeable.

Can I have surgery if I have dry eye already?

Pre-existing dry eye should be treated and stabilised first. Significant untreated dry eye is a reason to defer, and in some cases to choose a different procedure. It is not automatically disqualifying, but it must be assessed honestly.

How long do I stop wearing contact lenses before the assessment?

Contact lenses distort corneal shape and must be out before topography. Typical guidance is around one to two weeks for soft lenses and considerably longer for rigid gas permeable lenses. Confirm the exact period with the clinic and build it into your travel plan - arriving without having done this wastes the trip.

Before you book

Ask for your corneal thickness, topography result and residual stromal bed calculation, and ask the surgeon to explain why the recommended procedure fits those numbers. Ask how many of each procedure they perform annually. Ask what their approach would be if you are under-corrected at three months. Compare clinics on the completeness of the workup rather than on the advertised price.

Sources and further reading

This article is general information and not medical advice. Refractive surgery candidacy can only be determined by a licensed ophthalmologist after a full pre-operative examination.