Here is Lens Factor to corresponding A constant for Barrett Universal II. Earlier in video presentation https://www.quickguide.org/post/the-science-behind-barrett-universal-ii-formula,I have in detail explained about the concept of Lens Factor (LF). In that post I had explained that the Lens Factor, is the distance from the Iris plane to the second principal plane of the IOL. To understand more about what is second principal plane, a term derived from Gaussian Optics, please follow (https://www.quickguide.org/post/all-about-gaussian-optics-gullstrand-eye-theoretical-and-ray-tracing-formula).
In the below table, you get an idea on the A constant to Lens Factor conversion.
To understand more about Lens Factor (LF) and Barrett Universal formula, please visit:
(Note :Suggested Guideline only. Please use your own judgement before applying. quickguide.org does not guarantee the accuracy of the conversion factor and is a suggestion only.)