SMILE — flap-free vision correction through a small incision
The short answer
SMILE (small incision lenticule extraction) does not create a corneal flap. A laser forms a thin disc of tissue — a lenticule — inside the cornea, which is then removed through a small incision at the edge of the cornea. Gangnam Central Eye Clinic performs Smart SMILE LASIK on the SCHWIND ATOS, and Smart Nova LASIK, which adds CenTrax automatic centration before and during surgery. It is not recommended when the remaining corneal thickness is calculated to be below 400 and the cornea is also asymmetric or bulges at the back.
How does SMILE work?
- Because the lenticule is removed through an incision at the edge, there is no step in which a flap is lifted.
- Equipment: SCHWIND ATOS NOVA. According to the manufacturer's catalogue, the laser repetition rate is "up to" 4 MHz.
- What CenTrax adds in Smart Nova LASIK: the surgical laser automatically refers to images from the diagnostic device, recognises the pupil and follows eye movements, automatically corrects cyclotorsion (the slight rotation of the eye when you lie down), and corrects any positioning error remaining after docking. The manufacturer's catalogue describes this function as "particularly advantageous for correcting astigmatism".
- It is the measurements, not the laser, that decide the plan: 3D corneal topography (SIRIUS) is used to compare the astigmatic axis measured while you sit with the axis when you lie down for surgery.
Comparison — Smart SMILE LASIK, Smart Nova LASIK and Safe ATOS LASIK
| Corneal flap | How vision is corrected | |
|---|---|---|
| Smart SMILE LASIK | Not made | A lenticule is formed inside the cornea and removed through a small incision at its edge |
| Smart Nova LASIK | Not made | Smart SMILE LASIK with CenTrax automatic centration added before and during surgery |
| Safe ATOS LASIK | Made | The flap is lifted, the cornea is reshaped with an excimer laser, and the flap is laid back |
Who is SMILE suitable for — and when is it not recommended?
These criteria were set by the doctors themselves.
| Test result | What is advised |
|---|---|
| Remaining corneal thickness calculated below 400, together with corneal asymmetry or posterior corneal bulging on the Pentacam | SMILE is not recommended |
| A planned ablation of 160 or more, or myopia of -8.0 D or more with moderate astigmatism | Implantable lens surgery, which does not reshape the cornea, is recommended first |
| A low corneal endothelial cell count, an anterior chamber depth of 2.8 mm or less, or an anterior chamber angle below 25 | Implantable lens surgery is not recommended either |
| Severe dry eye | The dry eye is treated first |
Examination and surgery
- The key measurements are corneal thickness and shape, and they are taken several times to reduce the margin of error.
- Contact lenses before the examination: soft lenses out for at least 5 days, hard lenses for at least 7 days.
- Anaesthetic eye drops are the standard anaesthesia.
- On the day of surgery, it is recommended that someone comes with you, and driving yourself is not recommended. Your vision may be hazy and your eyes may feel irritated for a while, but getting home is not a problem.
- Patients who have Smart SMILE LASIK receive a surgery certificate showing which equipment was used.
Recovery and follow-up
| Guidance | |
|---|---|
| Daily life | From the next day; vision stabilises over 1 week to 1 month (varies by person) |
| Follow-up | The day after surgery, 1 week, 1 month, 2 months and 3 months; long-term follow-up between 6 months and 1 year; then a free check-up once a year |
| Flying | From the day after surgery, if the check-up that day shows the corneal surface is healing well. Cabin air is very dry, so use artificial tears more often than usual |
| Alcohol | A little after 2 weeks; heavier drinking after 1 month |
| Coloured (circle) contact lenses | Recommended only after 1 month, once the cornea has settled; the doctor recommends waiting 2 months if you can |
| Sunglasses | For at least 1 month when outdoors |
| Exercise | Walking from the next day; gym and yoga after 1–2 weeks (light weights within the first week are fine); swimming, combat sports and ball sports after 1 month |
How are costs explained?
Costs depend on your examination results and on the type of surgery, and fees for international patients are given after consultation. If you contact us by telephone or email before you travel, we will explain in advance so that nothing comes as a surprise when you arrive.
If you are travelling from abroad
- With SMILE, the first follow-up is the check-up the day after surgery. If that check-up shows the corneal surface is healing well, you can fly from that day. Please plan your trip so that you can attend this next-day check-up.
- How the later follow-up visits (1 week, 1 month and so on) will be handled after you return home is decided with you at consultation.
- Contact: telephone +82-2-555-1369 · email gnceyecenter@naver.com · WhatsApp · consultation languages on the registration: Korean, English and Chinese
Side effects and individual differences
Vision correction surgery carries the possibility of side effects, including dry eye, glare or halos at night, fluctuating vision during recovery and, rarely, infection, regression of myopia or the need for further treatment. Results and recovery differ from person to person, and no particular level of vision is promised. Please decide only after a precision examination and consultation with your doctor.
Results differ from person to person, and no particular level of vision is promised.
Frequently asked questions (20)
Does SMILE involve cutting a corneal flap?
No. A lenticule formed inside the cornea is removed through a small incision at its edge.
What is the difference between Smart Nova LASIK and Smart SMILE LASIK?
Smart Nova LASIK is Smart SMILE LASIK with CenTrax automatic centration added before and during surgery. Neither creates a flap.
I've been told my corneas are thin. Can I have SMILE?
If the remaining corneal thickness is calculated to be below 400 and the Pentacam also shows corneal asymmetry or bulging at the back, SMILE is not recommended. In that case, implantable lens surgery, which does not reshape the cornea, is considered as well.
SMILE, LASEK or ICL — which is right for me?
Your test results decide. For SMILE and LASEK the key factors are corneal thickness and shape; for ICL they are the depth, angle and space of the anterior chamber.
Is one type of surgery safer than the others?
No single method is always safer than another. What matters is whether the method has been chosen for your eye on the basis of the measurements — and if your eye does not meet the criteria, that surgery is not recommended.
Can I go to work the day after surgery?
With SMILE, normal daily life is possible from the next day, and vision takes 1 week to 1 month to stabilise. This varies from person to person.
When will I reach 20/20 (1.0) vision?
No particular level of vision is promised. Vision is expected to stabilise within 1 week to 1 month; the 1-month check-up looks at whether the correction has settled, and a final visual acuity check is done at 3 months.
When can I fly after SMILE?
From the day after surgery, if the check-up that day shows the corneal surface is healing well. The cabin air is dry, so use artificial tears more often than usual.
Can I come on my own?
It is recommended that someone comes with you. Driving yourself on the day of surgery is not recommended, so please use public transport or have someone drive you.
When can I drink alcohol again?
A little alcohol from 2 weeks after surgery, and heavier drinking from 1 month.
When can I wear coloured (circle) contact lenses?
From 1 month after surgery, once the cornea has settled — and the doctor recommends waiting 2 months if you can. These lenses let little oxygen through, so it is better not to wear them for long periods.
Do I really have to wear sunglasses?
Sunglasses or UV-blocking glasses are recommended outdoors for at least 1 month.
When can I exercise?
Walking from the next day, gym and yoga after 1–2 weeks, and swimming, combat sports and ball sports after 1 month.
Does it hurt? What kind of anaesthesia is used?
Anaesthetic eye drops are standard, and being put to sleep is, as a rule, not necessary. After surgery, your vision may be hazy and your eyes may feel irritated for a while.
Can SMILE correct high astigmatism?
The decision is made after checking the astigmatic axis and the condition of the cornea. The manufacturer's catalogue describes CenTrax in Smart Nova LASIK as advantageous for correcting astigmatism, but whether it applies to you is judged from your examination.
What are the chances of side effects?
It is not given as a number. The examination first looks for conditions that raise the risk, such as severe dry eye or high astigmatism, and anything that can be treated is treated first.
Will I get a surgery certificate?
Patients who have Smart SMILE LASIK receive a surgery certificate showing which equipment was used.
What happens if my vision gets worse again?
Revision surgery is not suggested straight away; first it is established whether the cause is regression of myopia, the optic nerve or retina, or an early cataract. If it is within 7 years of the first operation and the examination shows that revision is possible, revision surgery is offered free of charge.
Can international patients have SMILE here?
Yes. The clinic is registered as a medical institution for foreign patients (M-2021-01-08-6311), and the consultation languages on that registration are Korean, English and Chinese.
How much does it cost?
It depends on your test results and the method, and fees for international patients are given after consultation.