EVO ICL in Korea with high astigmatism: can one lens correct it? Often, if your eye has room
If your glasses prescription reads something like -9.00 -3.75 × 180, EVO ICL in Korea with high astigmatism is a plan many eyes can follow: the lens comes in a toric design that corrects the astigmatism together with the nearsightedness, and it sits inside the eye without any corneal tissue being removed. The worry that follows is more specific. A toric lens only corrects astigmatism while it stays at the angle it was placed, so what happens if it turns after you've flown home?
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What a toric EVO lens does with astigmatism
With a high cylinder number, that map is the first thing I want to see.
If your latest glasses or contact-lens prescription is on your phone, send that photo on WhatsApp with the cylinder and axis readable, and ask the one question that's holding you back, whether it's rotation, your age or night driving.
Astigmatism means the front of the eye, usually the cornea, curves more steeply in one direction than the other, so light comes to a focus at more than one point. The US National Eye Institute describes the result as blurry or distorted vision at any distance. A toric ICL carries the opposite curvature built into the lens and is lined up along your astigmatism axis, the same job your glasses do from the outside.
Because the cornea isn't reshaped, the thickness of your cornea doesn't cap the correction the way it does with laser surgery. That's why an implantable lens enters the discussion for three groups: high myopia, thin corneas and dry eyes. You can see how the procedure itself works on our EVO/EVO+ ICL lens implant page.
If your corneas are thick enough and your astigmatism is moderate, laser belongs in the same conversation. How corneal thickness splits LASIK from LASEK covers that side of the decision.
How much astigmatism can one lens carry?
Approved ranges are set country by country.
Labelling in Korea isn't necessarily identical, so ask at booking which range applies to the lens planned for your eye.
When the cylinder sits beyond what one lens is designed to carry, I'd rather change the plan than stretch the lens. Which of Smart Nova LASIK, LASIK, LASEK or an ICL fits your eye is confirmed after the full exam.
Is your astigmatism regular, or a warning sign?
High astigmatism is sometimes the first visible sign of keratoconus, where the cornea thins and bulges forward over time. That kind of astigmatism is irregular and tends to keep changing, and a fixed lens can't keep up with a cornea that's still moving.
Our first-visit exam includes corneal topography, which maps the curvature and shape of the corneal surface to detect keratoconus and irregular corneas, followed by a slit-lamp exam with the doctor.
When the cylinder is high, I read the topography before I think about lenses. A cornea that steepens in one area makes me slow down, because the first job then is protecting the cornea, for instance with corneal cross-linking. Keratoconus treatment and cross-linking both sit within our vision correction center, so a warning sign on the map changes the order of things rather than closing the door.
Which exam numbers decide whether a lens fits?
Four measurements carry most of the weight, alongside the topography above.
- Stability of your prescription. If your cylinder or axis has moved over the past year, the eye isn't ready for any surgery, lens or laser.
- Anterior chamber depth. This is the space between the cornea and your natural lens, where the ICL sits. The US labelling asks for 3.00 mm or more.
- Endothelial cell count. These cells line the back of the cornea and don't regrow. The FDA lists progressive loss of them among the risks of phakic lenses, so the starting count matters.
- Eye pressure. Our exam treats 10 to 20 mmHg as the normal range, and a higher reading leads to a detailed glaucoma exam. Raised pressure is another risk the FDA names for these lenses.
Lens size ties these together. An ICL that's too short for the eye can sit too close to your natural lens or turn more easily; one that's too long can push the iris forward and raise pressure. Ask how the size was chosen, and after surgery ask what the vault looked like, meaning the gap between the ICL and your own lens.
What happens if a toric lens rotates?
In short, it corrects less astigmatism. By the standard optical rule of thumb, each degree off axis costs roughly 3 percent of the correction, so a lens that turns about 30 degrees leaves you with about as much astigmatism as before, on a different axis.
When rotation happens, it most often shows up in the early period after surgery, and the usual fix is a short second procedure to turn the lens back or exchange it for a different size. Rotation is the part of EVO ICL in Korea with high astigmatism that the trip has to be planned around.
That's why I'd rather the early checks happen in Seoul.
Before you fly, ask for a note of the lens model, its power and the axis it was placed on. An ophthalmologist at home can compare that axis with what they see at the slit lamp.
Risks to weigh before you book
An ICL leaves the cornea untouched, yet it is still surgery inside the eye. The FDA's list of phakic lens risks includes cataract formation, gradual loss of endothelial cells, raised eye pressure and glaucoma, retinal detachment, glare, halos and double vision, and loss of vision. Some of these lead to further surgery to reposition, replace or remove the lens.
Night halos deserve a separate word for high prescriptions. A pupil that opens wide in the dark can reach past the optic of the lens, and lights can look ringed. Many people adapt over weeks; some don't, and if you drive at night for work, that matters.
Serious visual side effects, although rare, have occurred when surgery went ahead despite an examination result advising against it. So if your measurements say no, I'll say no, and that applies to every procedure on our list. Results vary from eye to eye, and suitability is decided at the in-person exam.
If you're in your forties
Near focus fades for nearly everyone from the early-to-mid forties, which the American Academy of Ophthalmology describes as presbyopia. An ICL corrects distance; it doesn't restore reading vision, so plan on reading glasses at some point even if your distance vision is clear.
Cataract is the other long-range question. If one develops years later, the ICL is usually removed during cataract surgery.
If you're in your mid-forties with a strong prescription and high astigmatism, a lens is still worth discussing, but I'd want you to look at the next fifteen years, not only the next flight. Our cataract and presbyopia center is part of the same clinic, so that longer conversation can happen with the doctors who focus on it.
If you've had an eye exam at home that printed a corneal topography map or a pressure reading, a photo of those pages on WhatsApp, with a line saying how many years you've worn contact lenses, is a useful place to begin.
Results vary by individual.
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Questions answered
Can an ICL be taken out later if I change my mind?
An ICL can be removed or exchanged in a further operation, which is why it's often described as reversible. That second operation carries its own risks, so treat removal as a fallback rather than part of the plan.
Is ICL an option if my eyes are dry or my cornea is thin?
Those are two of the situations where an implantable lens is considered, along with high myopia, because no corneal tissue is removed. Whether it suits your eye comes down to measurements such as anterior chamber depth, endothelial cell count and eye pressure.
Which languages are spoken at Sky Eye Clinic?
The clinic lists English, Japanese and Chinese, and its WhatsApp Business channel is listed as English.
Which days can I come in for an exam?
Monday to Wednesday and Friday from 10:00 to 16:30, with lunch from 13:00 to 14:00. Saturday runs 10:00 to 14:30 for exams and surgeries only. The clinic is closed on Thursdays for equipment inspection and on Sundays and public holidays. All exams are by appointment.
How do I get to the clinic?
It's about a five-minute walk from Nonhyeon Station (Line 7 Exit 5, or Sinbundang Line Exit 4) or from Sinnonhyeon Station (Line 9 Exit 2). The address is 723-26 Banpo-dong, Seocho-gu, Seoul.
Get your free consultation before you decide
- Free consultation and checkup, even if you decide against surgery
- Same price as Korean patients, no overseas surcharge
- Interpreters in English, Japanese and Chinese
