Physician Downloads & Calculators

Correcting for Vertex Distance — Vertex.xls (Excel)

Be sure to maintain the correct sign (+ or -) when entering the refractive data, or the results will not be accurate.

PHYSICIANS ONLY. Requests from technicians or staff are NOT allowed and will be returned or ignored.  Dr. Hill dedicates a significant amount of his personal time to completing each Haigis Optimization, doing so without compensation. He only accepts requests directly from the surgeon whose data it represents. Requests from personnel are never processed.

1. Instructions
This document provides a set of detailed instructions on how to complete and submit the Excel spreadsheet used to derive your set of surgeon- and IOL-specific a0, a1, and a2 Haigis constants for optical biometry.

Follow these instructions PRECISELY.
Haigis-Spreadsheet-Instructions.pdf (Adobe PDF)

2. Spreadsheet
This Excel spreadsheet is used to submit data for optimizing the a0, a1, and a2 constants for the Haigis formula. The corneal power must be entered in diopters, not millimeters. If fewer than 200 valid cases are submitted, only the a0 Haigis constant will be optimized, with the Haigis a1 and a2 constants set to their default values. Ideally, you would submit a minimum of 225 cases, so at least 200 instances will remain after the exclusion of possible outliers.

Haigis Formula Optimization — Haigis-Data-Collection.xlsx (Excel)

3. Email
Subject line must read: “Haigis Optimization”.

You must include the following:

  • Your name (only direct requests from the surgeon are allowed or accepted).
  • Haigis-Data-Collection.xlsx spreadsheet – complete and accurate
  • Manufacturer and model of each IOL, such as Alcon SN60WF
  • The biometry method employed, such as Lenstar or IOLMaster

CLICK HERE to email your completed spreadsheet

IOLMaster_User_Guide.pdf (Adobe PDF)

This PDF file contains the IOLMaster – A Practical Operation Guide, as provided by Carl Zeiss Meditec.

IOLMaster Checklist.pdf (Adobe PDF)

This PDF file contains the checklist that our staff uses when measuring the axial length, central corneal power, ACD, and horizontal corneal diameter using the IOLMaster. The PDF includes three identical checklists. We suggest having multiple copies laminated to allow each staff member access to their own.

Lenstar® User Manual.pdf (Adobe PDF)

This PDF file contains the Lenstar® User Manual, as provided by Haag-Streit-USA.

Refractive Vergence Formula — R-verg-Hill.xls (Excel)

This Excel spreadsheet contains the refractive vergence formula as outlined in:

  • Holladay JT: Standardizing constants for ultrasonic biometry, keratometry, and intraocular lens power calculations. J Cataract Refract Surg 1997;23:1356-1370.

The more sophisticated “Holladay R Formula” is recommended and is part of the Holladay IOL Consultant software package.

This PDF file contains the handout for Dr. Hill’s presentation given on May 5, 2019, at ASCRS.

NOTE: This is a HUGE pdf file. It may take a long time to load into your browser. Click on the link, and once the file has finished loading in the browser, you can save it to your computer.


Some physicians have expressed the desire to donate. Dr. Hill volunteers a significant amount of his time and resources to make the information on this website available. If you want to help cover some website expenses or say thank you, your contribution is welcome and graciously received.