ICL (implantable lens surgery) — vision correction without reshaping the cornea
The short answer
Implantable lens surgery corrects vision by placing a lens with your prescription inside the eye, without reshaping the cornea. It is considered first for eyes with a prescription so high that a great deal of cornea would have to be removed, and it is not recommended if the space inside the eye (anterior chamber depth and angle) or the corneal endothelial cell count falls short of the criteria. If the examination finds your eye suitable and the lens you need does not have to be custom-made abroad, surgery on the same day as the examination is possible.
How does implantable lens surgery work?
- The cornea is left as it is and a lens is placed inside the eye. Because the cornea is not reshaped, the lens can be removed if that becomes necessary — this is where it differs from LASIK and LASEK, where corneal tissue that has been removed cannot be restored.
- Lenses used: STAAR Aqua ICL and ECHO ICL. Which one is used depends on the space inside your eye and your prescription range.
- For patients with a high prescription who want a quick recovery, the doctors first recommend implantable lens surgery, "which preserves the eye as an organ rather than reshaping the cornea".
When is it recommended first — and when is it not recommended?
| Test result | What is advised |
|---|---|
| A planned ablation of 160 or more, or myopia of -8.0 D or more with moderate astigmatism | Implantable lens surgery is recommended first |
| A low corneal endothelial cell count | Not recommended (risk of endothelial cell loss) |
| Anterior chamber depth of 2.8 mm or less | Not recommended |
| A narrow anterior chamber angle below 25 degrees | Not recommended (risk of glaucoma) |
When same-day (1DAY) surgery is possible — and when it is not
- Possible: when the examination clearly shows your eye to be "suitable" and the lens needed is not in the range that has to be custom-made abroad (in the United States).
- Not possible: when the anterior chamber is not deep enough (generally 3.0 mm or more is needed; at some clinics from 2.8 mm) · when the condition of the cornea or eye is borderline and needs further observation · when there are after-effects from the dilation test · when contact lenses have not been left out for long enough · when your vision has changed within the last 6 months.
What does the examination look at?
For implantable lens surgery, the most important measurements are anterior chamber depth, anterior chamber angle and the space in the anterior chamber. These are measured several times to reduce the margin of error, and the corneal endothelial cell count, the prescription and astigmatic axis, eye pressure and the condition of the retina are checked as well.
- Corneal endothelial cells do not regenerate once damaged, so they are counted before surgery and taken into account.
- The lens size is chosen by measuring the anterior chamber angle and space. A lens that is too small can touch the natural lens and cause a cataract; one that is too large can block the flow of fluid inside the eye (aqueous humour) and cause glaucoma.
- If the lens sits off the astigmatic axis, some astigmatism remains, so the axis is measured separately and used to position the lens.
- Contact lenses before the examination: soft lenses out for at least 5 days, hard lenses for at least 7 days. After the dilation test, near vision is blurry and light feels glaring for 3–6 hours.
Recovery and follow-up
| Guidance | |
|---|---|
| Daily life | From the next day; settling 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 |
| Anaesthesia | Anaesthetic eye drops are standard |
| Hospital stay | Not required |
| Surgery certificate | Provided |
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. — The cost depends on the type of lens and the prescription range (including whether a custom-made lens is needed).
If you are travelling from abroad
- Same-day surgery is only possible when your eye is judged suitable and the lens does not need to be custom-made. If it does, surgery takes place after the lens has been ordered, which makes the schedule longer — please settle your travel dates at consultation once you have your test results.
- Take your contact lenses out before you leave home so that the examination on arrival is valid (soft lenses 5 days, hard lenses 7 days).
- When you can fly after implantable lens surgery is decided at the check-up the day after surgery.
- 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
An implantable lens carries the possibility of side effects, and these differ from person to person. Glare or halos at night can occur. A lens that is too small may touch the natural lens and bring on a cataract; a lens that is too large may impede the flow of fluid inside the eye and raise eye pressure, which can bring on glaucoma; inflammation of the iris or infection is possible. Corneal endothelial cells do not grow back once lost, which is why they are counted before surgery. No outcome is promised. Please decide only after a precision examination and consultation with your doctor.
A lens that is too small can touch the natural lens and cause a cataract; one that is too large can block the flow of aqueous humour and cause glaucoma; and with lenses that require the iris to be opened, inflammation of the iris (iritis) can occur if infection control is neglected. Results differ from person to person.
Frequently asked questions (18)
Does ICL surgery involve reshaping the cornea?
No. The cornea is left as it is, and a lens with your prescription is placed inside the eye.
Does the lens stay in my eye for life?
The lens stays inside the eye. Because the cornea is not reshaped, the lens can be removed if necessary — this is where it differs from LASIK and LASEK.
When is ICL recommended first?
When the planned ablation is 160 or more, or when myopia of -8.0 D or more comes with moderate astigmatism.
When is ICL not recommended?
When the corneal endothelial cell count is low, the anterior chamber depth is 2.8 mm or less, or the anterior chamber angle is narrower than 25 degrees — because of the risk of endothelial cell loss or glaucoma.
Can I really have surgery on the same day as the examination?
Yes, if the examination clearly finds your eye suitable and the lens is not in the range that has to be custom-made abroad. If the anterior chamber is shallow or the picture is borderline, another day is arranged.
How long does recovery take?
Daily life is possible from the next day, and things settle over 1 week to 1 month. This varies from person to person.
When will my vision reach 20/20 (1.0)?
No particular level of vision is promised. Your vision is measured again and checked at each follow-up visit.
Which lenses do you use?
Two types: STAAR Aqua ICL and ECHO ICL. Which one is used depends on the space inside your eye and your prescription range.
How is the lens size chosen?
By measuring the anterior chamber angle and space. A lens that is too small can touch the natural lens and cause a cataract; one that is too large can block the flow of aqueous humour and cause glaucoma.
Can I have ICL if I have astigmatism?
The astigmatic axis and power are measured separately and used to position the lens, because a lens that sits off the axis leaves some astigmatism behind.
I'm eligible for LASIK or LASEK — why does ICL cost more?
Instead of reshaping the cornea, a lens has to be placed inside the eye, and the cost varies with the type of lens and the prescription range. The exact cost is explained at consultation after your examination.
I've been told I can't have LASIK because my corneas are thin.
Implantable lens surgery does not reshape the cornea, so it is one of the options considered when the cornea is thin. Your anterior chamber depth and endothelial cell count must still meet the criteria.
When should I stop wearing contact lenses before surgery?
Soft lenses need to be out for at least 5 days and hard lenses for at least 7 days for the examination to be valid. Otherwise, the cornea is measured while still pressed out of shape.
Do I need to stay in hospital?
No. The surgery itself is short, but with preparation and checks, your visit takes longer.
When do I need to come back after surgery?
Check-ups are the day after surgery, then at 1 week, 1 month, 2 months and 3 months, with long-term follow-up between 6 months and 1 year.
Will I get a surgery certificate?
Yes, patients who have implantable lens surgery receive a surgery certificate.
Can international patients have ICL 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 the type of lens and your prescription range, and fees for international patients are given after consultation.