An ICL (Implantable Collamer Lens) is a phakic intraocular lens implanted between the iris and the natural crystalline lens to correct myopia and astigmatism. Unlike LASIK, it adds a lens rather than reshaping the cornea, and it is reversible.

ICL vs LASIK — which is better?

Neither is universally better; it depends on the eye. ICL is often preferred for higher prescriptions, thinner corneas, or dry-eye-prone eyes, while LASIK suits moderate prescriptions with fast recovery. Candidacy depends on the individual eye.

Who is a candidate for an ICL?

Typical candidates are adults with myopia (and up to moderate astigmatism) who want vision correction, especially those with high prescriptions or corneas not ideal for laser surgery. A full eye exam determines candidacy.

ICL — Implantable Collamer Lens

Name: ICL (Implantable Collamer Lens) — Overview
Creator: Gurpal Virdi, MD

An overview by Gurpal Virdi, MD · San Francisco Bay Area

An ICL (Implantable Collamer Lens) is a phakic intraocular lens — a thin, biocompatible lens implanted between the iris and your natural lens to correct nearsightedness and astigmatism. Unlike LASIK, it doesn't remove or reshape corneal tissue, and it can be removed. The current generation is the EVO ICL.

I'm a refractive and cataract surgeon whose research and engineering focus on ICL sizing — matching the right lens to each individual eye.

ICL vs LASIK

Neither is universally "safer" — it depends on your eye. ICL is often preferred for higher prescriptions, thinner corneas, or dry-eye-prone eyes; LASIK is common for moderate prescriptions with very fast recovery. The right choice comes from a careful evaluation, not a default.

Who is a candidate?

Typically adults with myopia (and up to moderate astigmatism), especially high prescriptions or corneas not ideal for laser surgery. A full eye exam — including anatomy and retina checks — determines candidacy.

How an ICL is sized

Sizing is the central technical challenge: the same eye can vault very differently across lens sizes. Traditional sizing relies on single formulas and nomograms — the OCOS (STAAR) nomogram, the Reinstein formula, the KS formula (Kamiya–Shoji), the NK formula (Nakamura), the Parkhurst and Dougherty nomograms, and the Kane ICL formula. I co-founded and lead engineering for ICL Fit, an AI-based ICL sizing agent — grounded in the peer-reviewed VAULT and VAULT-OCT research (JCRS) and a large, real-world dataset of EVO ICL surgical outcomes — that predicts the best-fit size and post-op vault for each eye instead of relying on one fixed formula. I trained at Parkhurst NuVision under Dr. Greg Parkhurst (of the Parkhurst nomogram), one of the most-published EVO ICL teams in the U.S. For the science and my peer-reviewed research, see the EVO ICL page.

Watch: ICL Sizing Methods

An introduction to ICL sizing methods and tips from Matt Hirabayashi, MD.

Also on YouTube and Instagram.

For patients: a full plain-language ICL guide — candidacy, recovery, risks, choosing a surgeon — is at ICLSurgery.com, which I co-review.

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Educational information, not medical advice. Discuss your specific eyes with a qualified ophthalmologist.