Zhang J, Shao J, Zheng L, et al. - Researchers conducted this retrospective study to compare the clinical accuracy of the newly developed Zhang & Zheng (ZZ) formula with previously reported intraocular lens (IOL) formulas. Post-corneal refractive surgery eyes were evaluated for IOL power utilizing the ZZ, Haigis-L, Shammas, Barrett True-K (no history), and ray tracing (C.S.O Sirius) IOL formulas, and their efficiency was compared. The sample consisted of 26 patients (38 eyes), aged 41 to 72 years. The ZZ IOL formula may provide better results for calculating IOL power in postcorneal refractive surgery eyes without prior refractive data.