ICL may be discussed for people who want vision correction but may not be suitable for corneal laser procedures such as LASIK. This may include patients with high myopia, thin corneas, dry eye concerns, or certain corneal measurements that make laser vision correction less suitable.
What Are Implantable Contact Lenses?
Implantable contact lenses are artificial lenses placed inside the eye to correct focusing problems. The natural lens of the eye is not removed, which is why ICL is sometimes described as a phakic intraocular lens.
The lens works by helping light focus more clearly on the retina. ICL may be used to correct refractive errors such as:
- Myopia
- Astigmatism
- Selected cases of hyperopia
- Higher refractive errors in patients who may not be suitable for laser procedures
ICL is different from cataract surgery. In cataract surgery, the cloudy natural lens is removed and replaced with an artificial lens. In ICL surgery, the natural lens remains in place.
Who May Be Suitable for Implantable Contact Lenses?
Suitability depends on eye measurements, prescription stability, eye health, age, lifestyle needs and doctor assessment. Not everyone who wants ICL will be suitable.
A patient may be considered for ICL if they meet several criteria after a detailed eye assessment.
1. Adults with a Stable Prescription
ICL is generally considered for adults whose spectacle or contact lens prescription has been stable for a period of time. If the prescription is still changing, surgery may be delayed because the correction may become less accurate over time.
Patients should bring previous spectacle or contact lens prescriptions to help the doctor assess stability.
The ophthalmologist may ask:
- How long has your prescription been stable?
- Has your myopia increased recently?
- Do you wear spectacles or contact lenses most of the time?
- Are there changes in one eye or both eyes?
- Have you had previous refractive surgery?
A stable prescription is one part of suitability, but it does not confirm eligibility on its own.
2. People with Moderate to High Myopia
ICL may be discussed for people with moderate to high myopia, especially when the degree of correction may be outside the preferred range for corneal laser procedures.
High myopia may also be linked to a higher risk of other eye conditions, such as retinal thinning or retinal tears. Because of this, patients with high myopia usually need a detailed eye examination before surgery is considered.
The eye specialist may check:
- Prescription strength
- Retinal health
- Corneal thickness
- Anterior chamber depth
- Eye pressure
- Optic nerve health
- History of retinal problems
Patients with high myopia should ask whether their retina needs assessment before ICL surgery.
3. People with Thin Corneas
LASIK and some other laser procedures reshape the cornea. If the cornea is too thin, laser correction may not be suitable.
ICL may be discussed because it does not depend on removing corneal tissue to correct vision. However, patients still need careful screening to check whether the internal eye space and overall eye health are suitable.
Thin corneas alone do not automatically make a patient suitable for ICL. Other measurements must also be reviewed.
4. Patients with Dry Eye Concerns
Some patients who already have dry eye symptoms may not be suitable for certain corneal laser procedures, or may need dry eye treatment before any refractive surgery is discussed.
ICL may be considered because the procedure does not reshape the corneal surface in the same way as LASIK. However, dry eye can still affect comfort, vision quality and recovery after eye procedures.
Patients should tell the doctor if they have:
- Burning or stinging eyes
- Grittiness
- Contact lens discomfort
- Redness
- Fluctuating vision
- Watery eyes
- Long screen use
- Previous dry eye treatment
The eye specialist may recommend dry eye assessment or treatment before deciding whether ICL is suitable.
5. Patients Not Suitable for LASIK or Other Laser Procedures
Some patients may explore ICL after being told they are not suitable for LASIK, SMILE, PRK, or other laser procedures.
Reasons may include:
- High prescription
- Thin cornea
- Irregular corneal shape
- Dry eye concerns
- Insufficient corneal thickness for the intended correction
- Previous eye surgery
- Other eye measurements that need caution
ICL is one possible alternative, but it is not suitable for everyone. A full refractive assessment is still needed.
6. People Who Want a Reversible Lens-Based Option
ICL can usually be removed or replaced if medically necessary. This is different from laser vision correction, where corneal tissue is permanently reshaped.
However, “removable” does not mean risk-free or temporary like a regular contact lens. ICL is still an eye surgery and should be considered carefully.
Patients should ask:
- Can the lens be removed if needed?
- What situations may require removal or exchange?
- What are the risks of removal?
- Would my eye return to the original prescription after removal?
- What long-term follow-up is needed?
Who May Not Be Suitable for Implantable Contact Lenses?
Some patients may not be suitable for ICL because of eye anatomy, eye disease, medical conditions, or surgical risk.
ICL may not be suitable if there is:
- Insufficient space inside the eye for the lens
- Shallow anterior chamber
- Abnormal eye pressure
- Glaucoma or high glaucoma risk
- Cataract or early lens changes
- Active eye infection or inflammation
- Certain corneal diseases
- Significant retinal disease
- Unstable prescription
- Pregnancy-related temporary prescription changes
- Uncontrolled medical conditions
- Unrealistic expectations about results
The doctor will explain if another option, monitoring, or no surgery is more appropriate.
What Tests Are Needed Before ICL Surgery?
A detailed pre-surgery assessment is needed before deciding whether ICL is suitable. The tests help assess eye health, lens sizing, surgical planning and risk.
The assessment may include:
- Vision testing
- Refraction
- Eye pressure measurement
- Corneal thickness measurement
- Corneal topography
- Anterior chamber depth measurement
- White-to-white measurement
- Pupil size assessment
- Dilated retinal examination
- Optic nerve assessment
- Tear film or dry eye assessment
- Endothelial cell count
- Review of previous prescriptions
- Discussion of lifestyle and visual needs
Not all clinics use the exact same testing sequence, but the aim is to confirm whether the eye can safely accommodate the lens and whether there are any conditions that may affect results.
Why Anterior Chamber Depth Matters
Anterior chamber depth refers to the space in the front part of the eye. This space matters because ICL needs enough room inside the eye.
If the space is too shallow, the lens may not sit appropriately. This could increase the risk of eye pressure changes, contact with eye structures, or other complications.
The ophthalmologist will measure this before deciding whether ICL is suitable.
Why Endothelial Cell Count Matters
The cornea has a layer of cells on its inner surface called endothelial cells. These cells help keep the cornea clear.
Before ICL surgery, the doctor may check the endothelial cell count. This helps assess whether the cornea is healthy enough for surgery and long-term monitoring.
Patients may need periodic checks after surgery, depending on their eye condition and doctor’s advice.
Why Retinal Assessment Matters for High Myopia
People with high myopia may have a higher risk of retinal thinning, holes, tears, or retinal detachment. Because ICL is often considered by patients with high myopia, retinal assessment is an important part of pre-surgery evaluation.
Patients should inform the doctor if they have:
- Flashes of light
- Sudden floaters
- Curtain-like shadow over vision
- Previous retinal laser treatment
- Previous retinal tear or detachment
- Family history of retinal problems
- Very high myopia
Any retinal concern may need assessment or treatment before refractive surgery is considered.
ICL vs LASIK: How Suitability May Differ
LASIK reshapes the cornea to correct vision. ICL places a lens inside the eye without removing corneal tissue.
ICL may be discussed when LASIK is less suitable due to high prescription, thin cornea, dry eye concerns, or corneal measurement issues.
However, LASIK and ICL have different risks, recovery considerations and long-term follow-up needs. The suitable option depends on the patient’s eyes, lifestyle and expectations.
Patients should avoid choosing a procedure based only on convenience or marketing claims. The decision should be based on proper assessment.
What Happens During ICL Surgery?
ICL surgery is usually performed as a day procedure. The eye is numbed, and the lens is inserted through a small opening. It is then positioned inside the eye.
The general steps may include:
- Pre-surgery checks
- Numbing eye drops or anaesthesia
- Small incision
- Lens insertion
- Lens positioning
- Eye pressure check
- Post-surgery medication and instructions
- Follow-up appointment
The exact steps may vary depending on the lens type, surgeon’s plan and patient’s eye anatomy.
Recovery After ICL Surgery
Recovery varies from person to person. Some patients may notice visual improvement early, while others may need more time for the eye to settle.
Patients may be advised to:
- Use eye drops as prescribed
- Avoid rubbing the eyes
- Attend follow-up visits
- Avoid swimming until cleared
- Avoid dusty environments where possible
- Avoid strenuous activity for a period
- Report pain, redness, or vision changes
- Follow instructions on work, driving and exercise
The doctor will advise when normal activities can resume.
Risks and Possible Complications
ICL is a surgical procedure and carries risks. Patients should understand these before deciding.
Possible risks may include:
- Raised eye pressure
- Infection
- Inflammation
- Cataract formation
- Glare or halos
- Under-correction or over-correction
- Need for lens repositioning, exchange, or removal
- Corneal endothelial cell changes
- Retinal complications in high myopia
- Need for further treatment
The risk level differs between patients. A detailed pre-surgery assessment helps identify factors that may affect suitability.
ICL Care in Singapore
Patients considering implantable contact lenses in Singapore should have a detailed refractive assessment with an eye specialist. This helps determine whether ICL, laser vision correction, spectacles, contact lenses, or another option may be suitable.
Dr Leo Adult & Paediatric Eye Specialist provides implantable contact lens assessment and treatment as part of its refractive eye care services. Patients can discuss whether ICL is suitable based on prescription, corneal measurements, eye pressure, retinal health and overall eye condition.
Implantable contact lenses may be suitable for selected adults with stable prescriptions, moderate to high myopia, astigmatism, thin corneas, dry eye concerns, or eyes that may not be suitable for LASIK or other laser procedures. However, suitability depends on detailed eye measurements and overall eye health.
A pre-surgery assessment may include vision testing, corneal measurements, anterior chamber depth measurement, eye pressure checks, retinal examination and other tests. Some patients may not be suitable due to shallow eye anatomy, glaucoma risk, cataract, unstable prescription, retinal disease, or other concerns.
Patients in Singapore considering ICL should ask an eye specialist about suitability, alternatives, risks, recovery, long-term follow-up and cost considerations before deciding.
FAQ
Who may be suitable for implantable contact lenses?
ICL may be suitable for selected adults with stable prescriptions, moderate to high myopia, astigmatism, thin corneas, or those who may not be suitable for LASIK. A detailed eye assessment is needed.
Is ICL only for high myopia?
ICL is often discussed for moderate to high myopia, but suitability depends on prescription, eye anatomy, corneal health, eye pressure, retinal health and other factors.
Can I get ICL if I have thin corneas?
Some patients with thin corneas may be considered for ICL because the procedure does not remove corneal tissue. However, other eye measurements must still be suitable.
Is ICL suitable for people with dry eyes?
ICL may be discussed for some patients with dry eye concerns, but dry eye still needs assessment and management before surgery is considered.
Who may not be suitable for ICL?
ICL may not be suitable for patients with shallow eye anatomy, unstable prescription, glaucoma risk, cataract, active eye inflammation, significant retinal disease, or other eye conditions that increase risk.
Can implantable contact lenses be removed?
ICL can usually be removed or exchanged if medically necessary, but removal is still a surgical procedure and has risks. Patients should discuss this with their ophthalmologist.
This article is for general information only and should not replace medical advice from a qualified healthcare professional.