The Ultimate Guide to Implantable Collamer Lens (ICL) Surgery in Singapore (2021)

Portrait of Dr Natasha Lim
Dr Natasha Lim

February 19th, 2021· 5 min read

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By: Dr Natasha Lim
Senior Ophthalmologist
Refractive Surgeon

Huge leaps in medical advancements have been made in the recent decade within the realm of ophthalmology and vision correction. One such intervention is Implanted Collamer Lenses (ICL) surgery — a recent breakthrough that has constantly been improved upon over the years to help rectify vision problems.

ICL surgery is a safe and effective vision correction procedure for conditions such as high myopia, which is very prevalent in Singapore. In fact, we are labelled “the Myopia capital of the world”, with a projected 80-90% of Singaporean adults with myopia by 2050 [1].

Let experienced ophthalmologist, Dr. Natasha Lim, take you through all there is to know about ICL surgery in Singapore, such as the benefits, patient eligibility, risks, and other common misconceptions.

What are Implanted Collamer Lenses?

ICL, commonly known as Implantable Collamer Lenses or Implantable Contact Lenses, is a type of contact lens positioned between the iris and your natural lens to help correct quality of vision.

These special contact lenses are surgically implanted into the eye and are made from a material called Collamer, which is biocompatible. Collamer is made up of a combination of polymer and collagen which also help to make the lenses lighter and more permeable for gas and nutrients. [2]

EVO Visian ICL

Evo Visian ICL

What is ICL surgery?

ICL Eye Surgery is a surgical procedure that involves safely implanting the ICL into the eyes. It is a form of refractive surgery that helps correct vision conditions such as:

  • Myopia - nearsightedness, when further objects appear blurry
  • Hyperopia - farsightedness, when nearby objects appear blurry
  • Astigmatism - irregular eye shape, causing blurry vision
  • Presbyopia - gradual loss of ability to focus close-up objects

Is ICL surgery permanent?

The ICL is permanent and will not change or become obsolete. However, with time, aging or injury may cause your eye health to deteriorate. For example, developing a cataract, or clouding in your eye.

If you develop a cataract, usually in your 60s to 70s, you will need to undergo cataract surgery to remove the cataract in order to correct your vision once again. This means that both the ICL that was implanted prior and the developed cataract would have to be removed and replaced by a different type of lens implant to restore your vision.

All in all, to a certain extent, the ICL lasts indefinitely until the day you may develop a potentially blinding eye disease of some sort, such as cataracts.

How long does an ICL surgery take?

It takes about 20 minutes for a set of eyes: 10 minutes per eye. ICLs are implanted in both eyes on the same day concurrently.

There will be a slight downtime of 5-6 hours of blurred and distorted vision postoperatively because of fully dilated pupils. When the pupils return to normal size, you should experience visual recovery within the same day and may resume work the very next day,

You should experience visual recovery within the same day and may resume work the very next day.

What are the benefits of getting ICL surgery?

The two most popular refractive surgery procedures at the moment are LASIK and ICL. In some cases, ICL can be a better option than LASIK to correct refractive error conditions.

In clinics that possess both LASIK machines and ICL apparatus, patient’s first choice would usually be LASIK to correct their refractive errors because it is much more affordable than ICL, at only a fraction of the cost.

While LASIK is a more affordable procedure, ICL may be better for some patients with under certain conditions. It is best to consult a qualified eye doctor to assess the best corrective eye procedure for you.

Patient suitability

After a pre-op examination of the eyes, some patients may be deemed unsafe or unsuitable for LASIK surgery. Their cornea thickness or corneal topography may not be sufficient for cornea-based procedures such as LASIK, PRK, LASEK or SMILE, or the patients may be suffering from extremely dry eyes.

For patients who are unable to undergo LASIK procedures for such reasons, ICL surgery would be an alternative option that can help achieve total spectacle freedom. It is an additive vision correction procedure that involves inserting ICLs into the eye, without involving the cornea.

Extent of vision correction

As all corneal based laser vision procedures involve thinning the cornea, they are limited by the thickness of the cornea and have to stop at a certain refractive power, which is usually -10.00 degrees.

On the other hand, ICL does not have a limit to the amount of vision correction you can undergo since since the lens is produced and customised for each individual.

People with more than -20.00 degrees of myopia can still undergo ICL, as ICL surgery is not restricted by corneal thickness.

Side effect of dry eyes

Another benefit of ICL is that it does not cause dry eyes. LASIK can cause dry eyes in patients with high myopia as a result of a deeper treatment affecting more corneal nerves responsible for stimulating tear production.

Regardless of the magnitude of vision correction required, ICL will not cause dry eyes because it does not take place at the cornea which affects tear production in the eyes.

Reversible procedure

Implantation of ICL is a totally reversible procedure, even after many years.

If for any reason you do not like the outcome of the procedure or if there are any big changes to the refractive power of your eye in the future, the ICL can be readily removed.

Regardless of whether it has been only a few months from the initial operation, or even it has been 30 years after the initial operation, it would be just as easy to remove the implants from the eye.

At around the age of 60 years old, most people develop cataracts which refer to the cloudiness of the natural lens inside the eye causing blurred vision. If you have had previous ICLs implanted in your 20s, 30s, or 40s, at the time of cataract surgery, the eye surgeon will remove the ICLs together with the cataracts; both will be replaced by a different type of lens implant which can also correct myopia, astigmatism, and presbyopia in order to help the cataract surgery patient achieve spectacle freedom.

eye consultaiton

When is the best time to do ICL surgery?

The FDA approves ICLs for patients from the age of 21 to 45 years old.

ICL surgery is FDA-approved for the age of 21 years and above because that is when you have refractive stability. Your eyes are fully developed and suitable for ICL surgery.

Ideally, the younger you do refractive surgery, the more mileage you get out of your investment.

If you were to undergo ICL surgery at about 40 years old, you may only get 20 years of use out of the ICLs as opposed to double that time period if you had undergone ICL surgery at 20 years old.

Cataracts may start to develop when you are around 60 years old and like most people, you may then undergo cataract surgery. In the end, you may not feel that the investment in ICL surgery has gone a long way if you had undergone ICL surgery at a later age, eg in your 40s.

Who cannot go for ICL surgery?

There are certain criteria that each patient has to satisfy to be deemed suitable for each vision correction procedure.

Unsuitable eye size

LASIK patients have entry criteria based on cornea thickness. On the other hand, ICL is based on entry criteria involving sufficient anterior chamber volume (space).

ICL patients are required to have adequate space in the eyes between the cornea and the iris, at 2.8mm³, to house the ICLs. The larger the eye, the more space there is to accommodate the ICL.

If your eyes are too small and cannot accommodate the lens, you will get an overcrowding effect in the eye if the ICL is implanted. Squeezing the ICL into a tight space may lead to a rise in eye pressure causing glaucoma or lens touch against important structures in the eye causing early-onset cataracts.

Pre-existing eye conditions

There are a few main eye conditions that make a patient unsuitable for ICL surgery such as:

  • Glaucoma

  • Cataracts

  • Retina disease

  • Autoimmune disease

  • Unstable refractive power

  • Narrow angles inside the eye

How should I prepare before my first consultation for ICL surgery?

First of all, when seeking a specialist for ICL surgery, it is best to look for a more experienced ophthalmologist.

The size of the lens implant is an important factor for ICL surgery. You may want to ask about the average eye volume that the eye surgeon works with when you are considering your options.

An eye check is required to see if you have an adequate chamber size. If you have decided on a specialist, you will be measured for the ICLs. It usually takes about 5 days for the custom lens to be produced and imported from Switzerland.

Getting ICLs in Singapore is interesting. Regardless of which surgeon or eye hospital you visit, all eye doctors send the measurements of your eye exclusively to one company in Switzerland, STAAR Surgical.

This is the only company in the world that designs, develops and manufactures implantable lenses for the eyes. Each lens is tailored to each patient and then delivered worldwide to the eye surgeon. Even though the surgeons you choose may be different, all patients will receive the same type of lens and same material.

What can I expect during an ICL surgery?

The patient will be anaesthetised for the ICL procedure to be performed. The techniques used may vary between eye surgeons in the type of anaesthesia that is utilised in the procedure.

The types of anaesthesia used can be:

  • General anaesthesia

The patient is put in a sleep-like state. Some institutions may still be using this and performing surgery on one eye at a time. It can be very time consuming and expensive this way.

  • IV (intravenous) sedation

A drug is administered through a needle into a vein to make the patient unable to feel pain. Some eye surgeons use this in major hospitals.

  • Local anaesthesia

A drug is administered with an injection to induce loss of pain sensation.

  • Topical anaesthesia

Special eye drops are utilised instead.

The type of anaesthesia used depends on the surgeon's experience and comfort level. The more experienced the surgeon is, the more likely they would use topical anaesthesia. Some surgeons may be less experienced and prefer to use IV sedation or general anaesthesia. Personally, I conduct ICL surgery procedures with topical anaesthesia.

If the thought of undergoing the surgery brings you discomfort, you can discuss this with your doctor and opt to be put in a sleep-like state. However, it is a point of note that this method would be more costly as you would also need an anaesthetic doctor.

How should I prepare for an ICL procedure?

Before coming in for measurements for ICLs, you should have abstained from contact lens usage for a couple of days. This ensures the accuracy of the measurements.

Before the surgery, you need to have been fasting for 4 hours for solid food and 2 hours for liquids. About 45 minutes may be required for the eyes to become fully dilated before undergoing the surgery, which takes about 20 minutes for both eyes.

Afterwards, you have to be prepared for about 2-3 weeks of antibiotics and anti-inflammatory eye drops to treat inflammation and prevent infection. You have to be dedicated to the 3 weeks of post-op regime.

How much does ICL surgery cost?

In general, ICL surgery for both eyes can range from $9,000 to $15,000, depending on the degree of the lenses, the type of anaesthesia used for the procedure and the doctor.

Unfortunately, like other vision correction procedures, ICL surgery is considered a cosmetic procedure and hence, not MediSave or MediShield claimable.

What are the possible risks of complications of ICL surgery?

If the size of the ICLs are not correct, complications may arise, which is why accurate pre-op measurements are crucial.

Think of ICLs like your wedding gown or your tailored suit — inaccurate measurements can lead to a poorly-fit and uncomfortable attire. The surgeon takes very detailed measurements of the inner dimensions of your eyes, which are then given to STAAR Surgical in Switzerland, who carefully determines the size of the lens for you to fit your eye perfectly.

The correct size of the lens has to be ensured so that post-operatively, the ICLs within your eyes should not move at all to prevent the risk of glaucoma or cataract formation.

However, even though detailed measurements were taken for the ICLs, there is still a rare chance that the ICLs may not fit properly. The implanted lenses may move differently within each eye, which then requires a size or position adjustment of the lenses. Although extremely uncommon, there is a 1% chance that you may have to undergo the procedure again [3].

In the rare possibility that the ICLs were not optimal, clinics usually offer patients a special rate so that you would not have to pay the full price all over again. It is similar to LASIK where you would pay a lower price if there is a need for enhancement with a second procedure, for any reason such as under or overcorrection of vision. Our clinic charges $250 for a 3 year period after the first LASIK procedure if required. For ICL surgery, it is $500 for a 3 year period to change the ICLs for properly sized ones in a second procedure.

How long do halos last after ICL surgery?

My clinic uses the latest generation EVO+ Visian ICL lenses which contain 3 small holes. The holes are designed to deal with issues that the previous generation lens had such as high eye pressure problems like glaucoma.

The new generation lenses are improved with special holes to facilitate water flow and reduce eye pressure problems.

However, because of that, patients may see the centre hole when it is newly implanted. For a period of time, you may see halos caused by the hole in the centre of the ICLs. Rest assured, with time, you become accustomed to the haloes in your vision and will no longer be able to see it anymore. Anecdotally, that time it takes to acclimatise is about 3 to 4 months.

What can I do and cannot do after ICL surgery?

After a successful ICL surgery, you can start to do all sorts of activities the very next day, with the exception of swimming, which you must avoid for a period of 3 to 4 weeks. All other activities such as gyming, jogging, washing your hair, can be resumed the very next day.

You are allowed to rub your eyes and even wear contact lenses. As ICL surgery does not alter the shape of the cornea, you can also use off-the-shelf contact lenses after surgery.

Are there any common misconceptions you would like to address?

“ICL surgery is more expensive than LASIK and is hence the better option”

Generally, people may have misconceptions that ICL surgery is better just because it is more expensive and some clinics may recommend it first because it is reversible.

I believe ICL is as good as LASIK, but the decision should depend more on whether the patient is eligible for LASIK. In the event that it is not, then ICL surgery comes in as an alternative. The patients who cannot undergo LASIK still have a plan B to go glasses-free.

My clinic offers both vision correction procedures like LASIK and ICL surgery. I would recommend LASIK first as it is more affordable and gives the same results as ICL. But if you cannot undergo a LASIK procedure because your cornea is too thin or your degree is too high, then I would recommend ICL surgery as a fallback plan.

“If the doctor detects issues with the ICLs post-operation but the patient does not feel that there is anything wrong, there is no need for a second procedure.”

This is another possible and crucial misconception ICL surgery patients may have.

As mentioned earlier, even with accurate measurements, there is still a chance the ICLs do not fit optimally after it has finally been implanted into the eye. The patient is unable to sense or feel if the lenses are too big or too small. The patient’s vision may be good after the first procedure but there may be unapparent issues with the ICL and only the doctor is able to determine if that is the case and recommend a second procedure.

Patients may feel that the doctor is pushing for an extra and unnecessary ICL procedure when that is untrue. Depending on the situation, a second procedure involving the exchange of the ICL size may be necessary to prevent possible complications such as raised eye pressure or cataract formation.

However, you may have heard of cases where patients go against the doctor’s advice to undergo a secondary ICL procedure, simply because they do not feel anything wrong with the size and fit of the lens. Years later, complications in the eye appear such as raised eye pressure or cataract formation which could have been avoided with a secondary ICL exchange procedure earlier on.

Therefore, it is very important that you trust your doctor and have proper communication.

happy girl after ICL surgery


ICL surgery is a safe and effective option for patients looking to correct their vision conditions, especially for those who are unsuitable for other procedures like LASIK. While it may be daunting to undergo a surgical procedure involving the eyes, knowing more about it and trusting your doctor can ensure a comfortable and pleasant experience.

If you have any more questions, head over to ophthalmologist Dr. Natasha Lim’s profile to have them answered.

I hope that you've found this guide useful, and perhaps gained more insight into the application process. Most of the admissions-related information (admin and logistics wise) can be found on the official NUS Faculty of Dentistry website.

To help yourself out, you should take note of what people look for when they look for a dentist.

This article was written by Dr Natasha Lim and published on Wednesday, 25 January 2017. Human medically reviewed the article on Wednesday, 25 January 2017. The last update was made on Friday, 18 September 2020.

Disclaimer: Opinions belong to the author and not to the platform.

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