Apparatus and methodology for inserting an intraocular lens (IOL) into an eye. The apparatus includes a cartridge for holding an IOL and a handpiece with a body member for receiving the cartridge, an injector rod that is receivable by the body member, and a drive mechanism that longitudinally oscillates the injector rod in the body member when a rotational force is applied about a longitudinal axis in a single direction. In other words, a constant rotation in a single direction of the drive mechanism causes the injector rod to move distally and proximally in discrete increments, with the distal increments being larger than the proximal increments. Accordingly, the injector rod urges an IOL out of the handpiece in a two-steps-forward, one-step-back manner, thereby minimizing or eliminating the chance of the injector rod engaging with the IOL.