Abstract: An intraocular lens inserter for use during cataract surgery for delivering an intraocular lens (IOL) loaded into an IOL cartridge into a patient's eye. The inserter comprises an outer shell housing containing a hydraulic housing. A hydraulic piston positioned within the hydraulic housing defines an annular hydraulic chamber. The hydraulic chamber is filled with a fluid via a fill port. A high pressure compression spring constantly urges the piston forwardly to pressurize the fluid in the hydraulic chamber. During use, a valve element operatively connected to a depressible operation button, controls bleeding of fluid from the hydraulic chamber, whereupon the forward tip of the piston is moved forwardly to mechanically deliver the intraocular lens from the IOL cartridge into the patient's eye.