Correction from inside the eye, with the cornea left as it is
An ICL corrects your vision with a lens placed inside the eye, just behind the iris. Nothing is cut away from the cornea, so it stays in its original shape.
At Sky Eye Clinic in Seoul the lens used is EVO/EVO+ ICL. It is often considered when laser correction is hard to perform, for example with high myopia, a thin cornea or dry eye.
ICL is short for implantable contact lens. Unlike a daily contact lens, it is placed inside the eye and stays there to correct your vision on a lasting basis.
The lens has to fit the space inside your eye, so precise measurement and the surgeon’s experience carry a great deal of weight.
Before the day itself, your corneal thickness, pupil size and retina are examined closely. The attending surgeon checks your eyes both before and after the operation.
Drops widen the pupil and numb the eye. With the anaesthetic in place, the procedure is not painful.
A small incision is made at the base of the cornea. This is the doorway for the lens.
The soft lens is folded and passed through the incision.
Inside the eye the lens opens and rests between the iris and your natural lens.
Older ICL designs needed a small opening made in the iris first, a step called an iridotomy, so fluid could circulate. EVO and EVO+ lenses have a 360 micrometer hole in the centre of the optic. Aqueous humour passes through it, so no iridotomy is needed, and the chance of raised eye pressure, cataract and glaucoma is lowered rather than removed.
| Lens feature | What it means for you |
|---|---|
| Collamer, a biocompatible material | Sits comfortably with the eye’s tissue, with less dryness and foreign body sensation |
| 360 micrometer central hole | Fluid circulates normally without an iridotomy |
| UVA and UVB filtering | Adds protection from ultraviolet light |
| Cornea kept intact | The clinic notes dry eye is not made worse, and glare and halos are reduced |
| Removable | A further operation can take the lens out if it is ever needed |
Because no corneal tissue is ablated, the clinic reports that the risk of myopia returning is very low, and that most people get back to everyday life from the next day. Your own recovery depends on your eyes and on how closely you follow aftercare.
If you have keratoconus, an ICL can be paired with corneal cross-linking. The order of treatment is explained on the keratoconus treatment page. For costs, see pricing.
No tissue is removed from the cornea. The lens enters through a small incision at the base of the cornea, and the cornea keeps its shape.
No. The 360 micrometer hole in the centre of the lens lets fluid circulate, which is the job the iridotomy did for older lens designs.
Yes. Because the cornea is not ablated, the lens can be removed in a further operation if needed, returning the eye to its earlier state.
High myopia or astigmatism that makes laser correction difficult is one of the reasons the clinic considers an ICL. Your corneal thickness, pupil size and retina are examined first, and your surgeon confirms whether it suits your eyes.
