LASIK, SMILE, LASEK, and ICL each fit different corneal thickness, refractive power, and lifestyle needs. Here is how Gangnam Central Eye Clinic decides which one fits you.
There is no single "best" vision correction surgery — the right option depends on your corneal thickness, refractive power, and lifestyle, and a proper candidate exam is what actually decides it. At Gangnam Central Eye Clinic in Seoul, four categories are offered — SMILE-type laser correction, flap-based LASIK, surface-only LASEK, and lens-implant ICL — and each one solves a different combination of problems. This guide walks through what separates them so you arrive at your consultation already knowing which questions to ask.
What is the actual difference between LASIK, SMILE, LASEK, and ICL?
All four correct the same problem — light not focusing correctly on the retina — but they do it through different mechanics on the eye.
- Flap-based LASIK (called "Safe Atos LASIK" in this clinic's naming) creates a thin corneal flap before reshaping the tissue underneath with an excimer laser, then repositions the flap.
- SMILE-type surgery (branded "Smart Nova LASIK" / "Smart SMILE LASIK" here) does not create a flap at all. A femtosecond laser carves a small lens-shaped piece of tissue (a lenticule) inside the cornea and removes it through a small opening, leaving the surface largely intact.
- LASEK ("One-Point LASEK") removes the corneal epithelium without a blade or brush before laser reshaping, which is why it is described as a fully laser-based ("all-laser") surface procedure. There is no flap and no lenticule extraction — the epithelium regrows over the treated surface during recovery.
- ICL (Implantable Collamer Lens) does not touch the cornea's shape at all. A soft lens is placed inside the eye, in front of the natural lens, functioning like a permanent internal contact lens.
Why would a surgeon choose SMILE or LASIK over LASEK, or vice versa?
The clinic's SMILE-type platform (SCHWIND ATOS NOVA) is capable of a repeat rate of up to 4 MHz and uses an intelligent centering system that automatically corrects for residual docking error during treatment — the manufacturer's documentation is specific that this benefits astigmatism correction in particular. Because SMILE avoids cutting a large flap, corneal surface nerves are less disrupted, which the equipment manufacturer's own literature associates with a lower likelihood of post-operative dry eye. LASEK, by contrast, is chosen for patients whose corneal shape or thickness makes flap creation less suitable, and its main trade-off is a longer initial comfort period — protective contact lenses are typically worn for three to five days, with visual stabilization over one to three months. LASIK flap-based correction sits between the two: faster initial comfort than LASEK, but a flap is created.
When does a surgeon recommend ICL instead of laser correction?
ICL becomes the primary recommendation — not laser correction — for two groups: patients whose calculated corneal ablation depth would be too high, and patients with high myopia (roughly -8.0 diopters or beyond) combined with moderate astigmatism. In those cases, preserving the cornea rather than removing tissue from it is treated as the safer long-term choice, and ICL also tends to allow faster visual recovery for high-power corrections. ICL is not recommended when a patient has a low endothelial cell count, an anterior chamber depth of 2.8mm or less, or a narrow anterior chamber angle under 25 degrees — these conditions raise the risk of endothelial cell loss or glaucoma after implantation, so laser correction or careful monitoring is discussed instead.
Comparison at a glance
| Procedure | Corneal flap? | Typical recovery to stable vision | Best fit when |
|---|---|---|---|
| SMILE-type (Smart Nova / Smart SMILE) | No — small lenticule extraction | Next-day normal activity; visual stability 1 week–1 month | Suitable candidates who want minimal corneal surface disruption |
| Flap-based LASIK (Safe Atos) | Yes | Faster initial comfort than LASEK | Standard laser correction candidates |
| LASEK (One-Point, all-laser) | No flap; surface epithelium regrows | Protective lens 3–5 days; stability 1–3 months | Corneal profile less suited to flap creation |
| ICL (implantable lens) | Not applicable — no corneal reshaping | Next-day normal activity; stability 1 week–1 month | High myopia, thinner cornea, or when corneal preservation is prioritized |
These are typical ranges; individual healing time depends on your exam results and how your eyes respond after surgery.
How is the decision actually made?
Every option above is only "correct" for a specific set of measurements, not a preference. The clinic's own stated approach is to run the key diagnostic tests — corneal thickness and shape for laser procedures, anterior chamber depth and angle for ICL — more than once, rather than expand the number of unrelated tests, specifically to reduce measurement error before recommending a method. If your numbers fall in a gray zone between two procedures, that repeated measurement is what resolves it, not personal preference for one brand name over another.
Frequently Asked Questions
Q1) I've heard LASEK is safer than LASIK because it removes less tissue. Is that true?
A1) This is one of the most common misunderstandings among patients. LASEK and LASIK differ in where the correction happens (surface vs. under a flap), not in how much corneal tissue is removed overall — the amount removed depends on your prescription and the calculated ablation depth, not on which of the two techniques is used. Which one is more appropriate for your eyes depends on your corneal thickness and shape, not a general safety ranking between the two.
Q2) Is SMILE, LASIK, or ICL "the safest" option overall?
A2) There isn't a single safest option across all patients — safety in this context means the option matched to your specific eye measurements. A patient with thin corneas and high myopia is safer with ICL than with laser correction; a patient with normal corneal thickness and low-to-moderate myopia has several suitable laser options. The exam determines which category you're in before "safest for you" can be answered.
Q3) Can I decide between these procedures without an in-person exam?
A3) No procedure should be chosen from online information alone. Corneal thickness, corneal shape (topography), anterior chamber depth, and current refractive power all need to be measured directly, since several of these are exclusion criteria for one method or another (for example, a shallow anterior chamber ruling out ICL). Bring your own prescription history to your consultation, but expect measurements to be repeated on-site.
Q4) Why do some clinics only offer one of these procedures?
A4) Offering all four requires the underlying equipment for each — a femtosecond platform for SMILE, an excimer laser for LASEK/LASIK, and ICL lens fitting and implantation capability. A clinic that offers only one method can only recommend that method regardless of your exam results, which is why it's worth asking directly what a clinic's full procedure range is before booking.
Q5) Does ICL mean I'll need glasses again eventually?
A5) The ICL lens is intended to remain in the eye long-term rather than be temporary. Whether it needs replacement or removal in the future depends on individual eye changes over time and is something your surgeon monitors at follow-up visits — this is a common question addressed directly during ICL consultations rather than something to assume either way in advance.
Visiting Gangnam Central Eye Clinic
Gangnam Central Eye Clinic is located at Teheran-ro 333, Sindo Venture Tower, 9th floor, Seoul — a short walk from Seolleung Station Exit 5 (stairs) or Exit 6 (escalator). Consultation hours are Monday and Friday 9:30–18:30, Tuesday and Thursday 9:30–19:30 (evening hours), and Saturday 9:30–15:30, with the clinic closed Wednesdays, Sundays, and public holidays. The clinic is a registered foreign-patient-treatment institution (registration no. M-2021-01-08-6311) offering consultation support in Korean, English, and Chinese.
This article is provided for general informational purposes. Outcomes and suitability vary depending on each patient's eye condition, and an accurate diagnosis and treatment plan can only be determined after an in-person consultation and eye exam with a licensed ophthalmologist. Depending on the individual, side effects such as bleeding, infection, glare, dry eye, or corneal haze may occur, and their severity can vary from person to person.