Prospective analysis of 269 eyes of 269 patients between 2017 and 2020, with axial length (AL) of 22mm or less. New principles for calculating IOL power were recently developed, including formulas based on paraxial ray-tracing (Barrett and Olsen) and based on artificial intelligence. The IOL power was calculated according to a number of formulas, with Hoffer Q used for the actual IOL power utilised in surgery. The authors demonstrated that the predicted refractive error (PE) and Standard Deviation (SD) was lowest with VRF-G, Naeser 2, Kane, K6 and Olsen formulas, and these are therefore considered most accurate for eyes with shorter AL. In contrast, formulas such as SRK/T had significantly higher absolute PEs and should be avoided in these circumstances. Previous studies showed that Hoffer Q and Haigis formulas are accurate in these eyes, but the former becomes less accurate when the anterior chamber depth (ACD) is less than 2.40mm.