In this retrospective case series, Cheng et al (p. 700) evaluated a new formula-manifest refraction (MR) biometry—for calculating intraocular lens (IOL) power when performing IOL exchange. Analysis of 167 patients found that MR biometry consistently outperformed the Barrett Rx formula, demonstrating a lower root mean square absolute error of the prediction error across different IOL exchange scenarios and achieving a higher percentage of eyes within ±0.25 D and ±1.00 D of the predicted refraction across all subgroups.