The Formulas: From Basics to Online Settings and the Era of Artificial Intelligence

The journey to accurately calculate intraocular lens (IOL) power began in the 1960s, as surgeons sought to replace bulky aphakic glasses with precise lens implants. Early formulas relied on basic optical principles but often failed in real-world settings due to oversimplified assumptions about eye anatomy [1]. A major breakthrough came in 1980 with the SRK formula, developed by Sanders, Retzlaff, and Kraff. This formula used a simple equation—linking axial length (AL) and corneal curvature (keratometry, or K)—to estimate IOL power [2]. Though imperfect, it laid the foundation for modern IOL calculations.