Noticing ZEISS AI IOL Calculator as a Formula Option in ZEISS VERACITY Surgery Planner? Here’s Why

If you’re a ZEISS VERACITY Surgery Planner pro, then you’ve likely noticed ZEISS AI IOL Calculator as a formula option when you review ZEISS VERACITY’s menu of formulas during surgical planning. During the first two years of using Veracity, I noticed that the ZEISS AI IOL Calculator rarely showed any results —but that’s starting to change.
What is ZEISS AI IOL Calculator? How can it improve your clinical offerings? And why would you opt for this formula over other more established formulas? Let’s explore.
What Is ZEISS AI IOL Calculator? And where do I find it?
To answer these questions, let’s first recap ZEISS VERACITY Surgery Planner’s value proposition.
Cataract surgeons who use ZEISS VERACITY Surgery Planner as their clinics’ central organizing philosophy follow similar protocols. First, they gather presurgical data on any of the numerous biometers that connect to ZEISS VERACITY. They, then rely on ZEISS VERACITY to collate those data. Once collated, the surgeon turns to ZEISS VERACITY for input on lens selection, refractive target, and a formula that best aligns with the patient’s desired postoperative outcomes—so long as those outcomes are compatible with the patient’s anatomy.
As my colleague Eduardo Besser, MD, has written elsewhere in this series, ZEISS VERACITY Surgery Planner widens the spectrum of formulas used in your clinic, thereby empowering you to reach refractive targets best suited to the lens and postsurgical refractive goals your patient chose. Lately, many users have observed that ZEISS AI IOL Calculator has appeared as a formula option alongside more conventional formulas within ZEISS VERACITY’s interface.
ZEISS AI IOL Calculator is a data-driven IOL power calculation algorithm that uses advanced AI and paraxial ray tracing to generate crowdsourced IOL power calculations for specific IOL models.1 This formula relies on high-quality surgical and outcomes data from ZEISS-selected, world-class ZEISS VERACITY Surgery Planner users, which means its outputs are the dividend of investing in top-tier input data.
Importantly, ZEISS AI IOL Calculator provides no A-constant. Instead, it relies on more than 16,000 IOL parameters to fine tune its predictions for a given IOL model and constantly evolves as more data are input into the algorithm.
Why Am I Seeing ZEISS AI IOL Calculator as a formula option now?
ZEISS VERACITY Surgery Planner was programmed to not allow ZEISS AI IOL Calculator as a formula option until a specific surgical volume was reached. ZEISS AI IOL Calculator adjusts the exact volume for a given lens model based on several factors, but a good rule of thumb is that approximately 1000 cases must be input into ZEISS AI IOL Calculator’s algorithm before a formula for that IOL model is available.
After a requisite number of surgeries have been performed by select ZEISS VERACITY Surgery Planner users for a given lens—and after AI determines that the quality of input data reaches or surpasses the high threshold for quality set by ZEISS engineers—then ZEISS VERACITY offers the formula from ZEISS AI IOL Calculator as an option.
Lately, more lenses have become trained and made available on the ZEISS AI IOL Calculator formula, which means you may start to see it appear as an option under your IOL Formulas tab more often for your preferred lenses. This is because the preset minimum threshold for surgical volume of a given IOL model has been reached, which has unlocked ZEISS AI IOL Calculator to more users of ZEISS VERACITY Surgery Planner.
The best news? ZEISS AI IOL Calculator formulas are coming online for a variety of premium IOL models, giving practices driven by premium lens surgery a chance to use AI- and expert-driven formulas. When those lenses become trained on this AI, we should start to see a much higher adoption of this formula moving forward!


Figure 1. Holladay et al found that ZEISS AI IOL Calculator’s formula had the lowest mean absolute error among the crop of formulas analyzed.
Figure 1. Holladay et al found that ZEISS AI IOL Calculator’s formula had the lowest mean absolute error among the crop of formulas analyzed.
Can I trust a formula generated via ZEISS AI IOL Calculator?
Holladay et al reviewed mean absolute errors (MAEs) of 7 formulas, including ZEISS AI IOL Calculator.2 These researchers found that ZEISS AI IOL Calculator had the lowest MAE (0.40) among the 7 formulas tested; MAEs of popular formulas such as Kane (0.44), Barrett (0.44), and Pearl-DGS (0.45) were at least 10% higher, which was statistically significant (Figure 1).
But perhaps you’re like me and want to see for yourself. If so, I advise doing what I did: compare the formula from ZEISS AI IOL Calculator to the formula generated by your preferred calculation (in my case, Barrett). I have found that the two formulas disagreed rarely on power, which reinforced for me that the formula from ZEISS AI IOL Calculator was accurate.
Prepare Your Clinic for ZEISS AI IOL Calculator
It remains undecided to what extent AI will shape our clinical and surgical workflows. However, it has become clear to me that AI-based formulas such as ZEISS AI IOL Calculator will certainly become more reliable and powerful in the future, and potentially become the preferred formula for many surgeons. Our patients will benefit from crowdsourcing datapoints from thousands of cases from ZEISS-verified surgeons, and our clinics will stand out as surgical centers that prioritize cutting-edge technologies that push the field forward.
Luckily for users of ZEISS VERACITY Surgery Planner, integration of ZEISS AI IOL Calculator is seamless—in fact, your clinic is already set up to consider this formula alongside formulas you might otherwise select.
Keep an eye out for new formula options from ZEISS AI IOL Calculator next time you power up ZEISS VERACITY Surgery Planner. As more IOL models come online, your practice will be given the opportunity to embrace AI in the most desirable way: with minimal friction and maximum potential.
To learn more about ZEISS AI IOL Calculator, visit this link.
The statements of the author reflect only his personal opinions and do not necessarily reflect the opinions of any institution with whom he is affiliated.
The author has a contractual or other financial relationship with Carl Zeiss Meditec, Inc. and has received financial support.
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1
Kenny PI, Kozhaya K, Truong P, Weikert MP, Wang L, Hill WE, Koch DD. Efficacy of segmented axial length and AI approaches to IOL power calculation in short eyes. J Cataract Refract Surg. 2023 Mar 17.
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2
Holladay JT, Wilcox RR, Koch DD, Wang L. Review and recommendations for univariate statistical analysis of spherical equivalent prediction error for IOL power calculations. J Cataract Refract Surg. 2021 Jan 1;47(1):65-77.