ICL Surgery FAQs
Blue Fin Vision® consultants answer the most common questions about Implantable Collamer Lens surgery, from suitability and recovery to risks and costs. The answers below reflect our consultant-led protocol and audited outcomes, so you can make an informed decision.
What is implantable collamer lens (ICL) surgery?
ICL surgery is a vision correction procedure where a biocompatible lens is implanted inside the eye to correct refractive errors. The lens sits between the coloured part of the eye (the iris) and the natural crystalline lens, working with your eye’s natural optics to provide clear vision. Unlike laser eye surgery, ICL does not involve removing any corneal tissue. The collamer material is similar to the collagen found naturally in your cornea and includes UV protection properties.
Am I a candidate for ICL surgery?
ICL surgery is typically recommended for patients aged 21 to 45, with selective cases considered up to 50, with a stable prescription. It is particularly suitable for those with moderate to severe short-sightedness (myopia up to -20D) and astigmatism up to 6.0 dioptres. ICL is often the preferred option for patients with thin corneas, chronic dry eyes or keratoconus who are not suitable for LASIK. Your consultant performs detailed assessments to confirm whether ICL is appropriate for your eyes.
How does ICL differ from LASIK?
The key difference is that LASIK reshapes the cornea by removing tissue, while ICL adds a lens inside the eye without altering corneal structure. ICL is reversible, meaning the lens can be removed or exchanged if needed, whereas LASIK permanently changes the cornea. ICL is often better suited for higher prescriptions and patients with thin corneas, while LASIK treats a wider range of refractive errors including hyperopia. Both procedures are performed under local anaesthetic drops with minimal discomfort.
Is ICL surgery painful?
ICL surgery is not painful. The procedure is performed under local anaesthetic eye drops, ensuring comfort throughout. Most patients describe only mild irritation during and after the procedure. You may feel slight pressure as the lens is inserted, but this is generally well tolerated. Any post-operative discomfort is typically mild and short-lived.
How long does ICL surgery take?
The procedure usually takes 20 to 30 minutes per eye. You will be under observation for 1 to 2 hours after surgery to monitor your intraocular pressure before being discharged. ICL surgery is performed as a day case, meaning you can go home the same day.
What can I expect during ICL surgery?
After anaesthetic drops are applied, your surgeon makes a tiny incision and inserts the folded ICL lens, which then unfolds inside the eye. The lens is positioned precisely behind the iris. Antibiotic drops and ointment are applied, and an eye shield may be provided to protect your eye from accidental rubbing. The procedure is minimally invasive with a very short recovery time.
How soon will I see improvement after ICL surgery?
Many patients notice improved vision on the same day of surgery. However, expect the most significant improvement within the first week as your eyes settle. Vision typically continues to stabilise over the following weeks. Your consultant monitors your progress at scheduled follow-up appointments.
What are vault measurements and why do they matter for ICL surgery?
The vault is the space between the implanted ICL and your natural crystalline lens. UK surgeons aim for a vault measurement between 250 and 750 microns, sometimes called the “Goldilocks zone”. A vault that is too low (below 250 microns) increases the risk of cataract formation, while a vault that is too high (above 750 microns) may cause elevated eye pressure or angle-closure glaucoma. Regular monitoring ensures the vault remains within the safe range. Under the ICL Lifetime Monitoring Protocol™, vault is tracked annually at defined intervals against this reference range.
Can the ICL be removed or replaced?
Yes, one of the key advantages of ICL surgery is its reversibility. The lens can be removed or exchanged if your prescription changes significantly, if a better technology becomes available, or if any issues arise. This flexibility makes ICL an attractive option for patients who want a non-permanent solution.
Blue Fin Vision® patients also have access to a pre-priced Post-ICL Cataract Surgery Pathway, set out in the ICL Lifetime Monitoring Protocol™, which defines long-term surgical options should cataracts develop in future.
Are there any risks associated with ICL surgery?
ICL surgery has a strong safety profile when performed by experienced consultants. Potential risks include infection, raised eye pressure, cataract formation and, rarely, endothelial cell loss. Modern ICL designs with central flow ports have reduced the need for peripheral iridotomy and lowered the risk of pupillary block. Detailed pre-operative measurements and structured monitoring under the ICL Lifetime Monitoring Protocol™ support early detection of any changes.
What is included in the ICL Lifetime Monitoring Protocol™ after ICL surgery?
Blue Fin Vision® includes the ICL Lifetime Monitoring Protocol™ with every ICL procedure, at no additional cost. Three clinical parameters are tracked for the life of the implant: endothelial cell density, ICL vault, and anterior segment health. Measurements are scheduled at defined intervals, compared against your own baseline, and interpreted against published clinical thresholds. Vault measurements are available at any Blue Fin Vision® clinic across London, Hertfordshire and Essex; endothelial cell counts are performed at our Harley Street centre. If a measurement crosses a defined threshold, a consultant-led review is arranged at no additional cost. See the full ICL Lifetime Monitoring Protocol™ for the schedule, inclusions and intervention thresholds.
