Background The capsular tension ring is a novel assistant tool for cataract surgery; however, controversy exists in its co-implantation. The potential for hyperopic or myopic shift resulting from the co-implantation of the capsular tension ring and intraocular lens remains unclear. This study aimed to determine the postoperative refractive prediction error and the direction of refractive shift in cataract patients who underwent capsular tension ring co-implantation.