| Written by GS Eye Clinic— Gangnam Seoul
Vision correction surgery can be broadly categorized into procedures like LASIK, LASEK, SMILE Pro, and ICL (Implantable Collamer Lens). The right procedure depends on your corneal thickness, degree of myopia, and overall eye health.
What matters just as much as the procedure itself is the pre-surgery examination. A thorough screening covers at least six areas — corneal thickness, retinal condition, dry eye severity, and more — to determine which surgery actually suits your eyes. It's not uncommon for previously undetected eye conditions to surface during this process.
This guide covers what a pre-surgery eye exam includes and how each procedure compares, so you can walk into your consultation informed.
What Gets Checked Before Vision Correction Surgery
A comprehensive pre-operative screening looks at your eyes from multiple angles — not just to measure vision, but to uncover conditions that could affect surgical safety or outcomes. Here's what each part of the exam evaluates.
The Six Core Areas of a Pre-Surgery Eye Exam
Exact methods vary between clinics, but the following should always be assessed.
1. Cornea test
Cross-sectional imaging captures each layer of the cornea at 0.002 mm resolution, automatically analyzing cell shape, size, density, and tissue structure.
- What this reveals: Your endothelial cell count, corneal thickness, and intraocular pressure — key factors in determining which procedures are safe for your eyes.
2. Retina test
The retina is tracked in motion to measure changes over time. Peripheral and three-dimensional retinal imaging allows for detailed evaluation.
- What this reveals: The vascular health of your retina, helping screen for conditions such as glaucoma, macular degeneration, and other retinal diseases.
3. Refraction Test
Using standard ophthalmic equipment — typically the "hot air balloon" autorefractor — your eye's refractive response is measured. Additional manual lens testing confirms visual acuity and astigmatism.
- What this reveals: Refractive power, corneal curvature, pupil size, and current visual acuity.
4. Xerophthalmia test
Specialized instruments examine tear film depth and the meibomian glands (a key tear-producing structure). A strip test placed on the eye directly measures tear secretion volume.
- What this reveals: The severity of dry eye. Significant dryness can affect surgical eligibility or require more attentive post-operative care.
5. Exophthalmos test
Precision instruments measure astigmatism, axial length, anterior chamber depth, corneal thickness, corneal refractive power, and pupil diameter.
- What this reveals: Whether your cornea can safely support a given procedure. These measurements are also essential for calculating the correct lens power for ICL or intraocular lens implantation.
6. Visual Field Test
A dedicated device evaluates the degree of optic nerve damage by mapping your field of vision.
- What this reveals: The presence and progression of glaucoma.
Before, During, and After Your Eye Exam
A few things to keep in mind for accurate results.
Before the Exam
- Stop wearing soft, toric, or rigid gas-permeable contact lenses at least two days before the exam.
- Orthokeratology (ortho-k) lenses require at least one month without use.
- Some exam methods may temporarily affect your ability to drive afterward. Confirm with the clinic in advance.
During the Exam
- The full screening takes approximately 1 to 2 hours. Once complete, a final consultation recommends the most suitable procedure.
- Additional tests may be performed depending on your eye condition — for example, dilating drops to obtain more precise refraction measurements.
After the Exam
- Depending on the clinic and method, same-day surgery may be possible.
- If dilating drops were used, your vision may remain slightly blurred until the following day.
SMILE Pro vs. LASIK vs. LASEK vs. ICL: Which One Fits?
The most suitable procedure is determined by your overall eye condition. If your eyes are healthy and your prescription is mild, you may be eligible for all four options.
The general guidelines below offer a starting point — but a proper screening is the only way to know for certain.
Quick Return to Daily Life → SMILE Pro
A type of LASIK, SMILE Pro removes only a small disc of corneal tissue through a tiny incision, minimizing scarring.
Total procedure time is around 10 minutes, with the actual laser application lasting roughly 10 seconds. Most patients return to work the next day.
Thin Cornea with a Strong Prescription or Astigmatism → LASEK
The corneal epithelium is gently removed, and an excimer laser reshapes the underlying cornea to correct vision.
Some discomfort is expected during recovery, but the procedure leaves the cornea structurally more resistant to impact. Recovery typically requires two or more days.
Very Thin Cornea or Extreme Prescription → ICL (Implantable Collamer Lens)
For patients whose corneas are too thin for laser-based correction, ICL offers a powerful alternative.
A custom-fitted biocompatible lens is implanted inside the eye — no corneal tissue is removed. While the lens cost places ICL at a higher price point, it delivers the highest visual quality among all options and is the only procedure that is fully reversible.
GS Eye Clinic Gangnam: Where the Surgeons Have Had the Surgery Themselves
There's a well-known saying in Korea: "Most eye doctors still wear glasses."
It's a line that questions the safety of vision correction — and it doesn't apply at GS Eye Clinic. Every specialist at GS Eye Clinic has either undergone vision correction surgery personally or performed the procedure on a family member.
This is one of the reasons The Pylon Square recommends GS Eye Clinic as a trusted vision correction partner.
- Over 70 categories of precision diagnostic testing with advanced equipment
- Unlimited post-surgery warranty
- Certified, original-equipment instruments, including Carl Zeiss (Germany)
Just as no two faces are alike, every pair of eyes has its own unique conditions. The optimal procedure is different for everyone.
A thorough examination — one that fully understands your eyes — is the foundation of a sound surgical plan.
Want a more detailed consultation or examination?
> Make an appointment via The Pylon Square.
[QnA]
Q1. Is it safe to get laser eye surgery in Korea as a foreigner?
Korea is one of the safest destinations in the world for laser eye surgery, and thousands of international patients undergo procedures every year. Korea's medical standards are internationally recognized, and top clinics in Gangnam operate under strict government licensing requirements. GS Eye Clinic is ZEISS-certified, holds international clinical approvals, and has performed over 300,000 procedures, every patient undergoes a comprehensive preoperative screening that includes corneal mapping, pachymetry (corneal thickness measurement), and refraction testing before any surgery is approved.
Q2. Is same-day consultation and surgery available at GS Eye Clinic?
Yes. For eligible patients, GS Eye Clinic offers same-day consultation and surgery. This option is especially popular with international visitors. However, we do not accept walk-in visits, and appointments must be scheduled in advance.
Q3. How long before surgery do I need to stop wearing contact lenses?
The pause time depends on your lens type, and it's one of the most important things to plan around before booking your flights to Seoul.
- Soft lenses (including colored lenses): at least 2 days before your consultation
- Astigmatic & hard lenses: at least 2 days before your consultation
- Dream Lenses (Ortho-K): at least 1 month before your consultation
Arriving without having stopped early enough is one of the most common reasons consultations need to be rescheduled, since lenses temporarily alter the shape of the cornea and prevent us from taking accurate measurements.
Q4. What is included in the surgery price at GS Eye Clinic?
The quoted price includes your initial eye examination, interpretation services, the surgery itself, and there are no hidden fees. Post-operative follow-up appointments are complimentary for 4 months after surgery, after which standard consultation fees apply.
GS Eye Clinic issues a warranty certificate to all patients, ensuring that care and further treatment remain available should any changes in vision occur after surgery.
Depending on your eye condition, additional diagnostic tests, treatments, prescriptions, or consultations beyond the standard pre-surgery evaluation may be required, and separate charges may apply.
Q5. How does the cost of LASIK in Korea compare to the US, UK, or Australia?
LASIK eye surgery in Korea is generally 40–60% less expensive than equivalent procedures in the US, UK, or Australia, with no compromise on technology or surgeon experience.
Standard LASIK is priced from approximately $1,000–$1,300 (both eyes), and SMILE Pro from approximately $2,800–$3,000 (both eyes). Promotional pricing may apply — final cost is confirmed at consultation.
GS Eye Clinic performs all procedures with the latest medical equipment and most international patients find the savings easily cover flights and Seoul accommodation.
| Edited by Sia Shin, The Pylon Square
