EVO ICL › Palo Alto
EVO ICL in Palo Alto
How the lens is sized, and what to ask · Gurpal Virdi, MD
Medically reviewed by Gurpal Virdi, MD, refractive and cataract surgeon and ICL-sizing researcher · Last reviewed: 25 August 2026
Peninsula patients tend to arrive having already read the primary literature, which is a good instinct, and the questions below are the ones worth bringing to a consultation. This page is written from the sizing side of the problem, which is where my research sits. For a general patient guide to candidacy, recovery and cost in Palo Alto, see the Palo Alto guide on ICLSurgery.com, which I co-review.
Why sizing is the question in Palo Alto or anywhere else
The EVO ICL comes in four sizes: 12.1, 12.6, 13.2 and 13.7 mm. The same eye vaults very differently across them. Too large and the lens sits high, crowding the drainage angle; too small and it sits low, close to your natural lens. The target range most surgeons work to is roughly 250–750 microns of clearance.
Traditional sizing uses white-to-white corneal diameter, an external measurement, as a proxy for the internal dimension where the lens actually rests. That is a correlation rather than a measurement, and it is why sizing-related exchange remains the most common reason an ICL is reoperated (Clinical Ophthalmology, 2025). My research, including the VAULT and VAULT-OCT deep-learning models published in the Journal of Cataract & Refractive Surgery, predicts vault directly from anterior-segment imaging instead.
Three questions worth asking any Palo Alto surgeon
Do you image the anterior segment, or size from white-to-white? AS-OCT or UBM measures the space the lens will occupy. White-to-white infers it.
What sizing method do you use? OCOS, Reinstein, KS, NK and the Parkhurst nomogram are all named methods with published performance. "Experience" is not a method.
What is your exchange rate? The most revealing question in the consultation. A surgeon who tracks it is measuring their own outcomes; one who has never calculated it is not.
The age range has changed, and most pages have not caught up
On 17 February 2026 the FDA expanded the EVO ICL age indication from 21–45 to 21–60 (STAAR Surgical). A great deal of currently published material, including pages from practices across Palo Alto and the wider Bay Area, still states the old range. If you are between 45 and 60 and were told you had aged out, that advice predates the change. See the full explanation.
For patients in Palo Alto and nearby
Patients researching EVO ICL from Palo Alto typically also search from Menlo Park, Mountain View, Redwood City, Los Altos and the mid-Peninsula. The clinical guidance does not change with the postcode — sizing method, imaging and exchange rate are the same questions everywhere — but the practices available to you do, and comparing them on method rather than on marketing is the useful exercise.
Related reading: what the FDA safety data actually shows, what EVO ICL costs and what a quote should include, and how LASIK and PRK compare.
Educational information, not medical advice. Discuss your specific eyes with a qualified ophthalmologist.