Abstract: An ophthalmic aspirator and cystotome having a hand-held, motorized instrument which is operated by a battery-run control system. The instrument includes a disposable coaxial aspirator-irrigator tip and a wormdrive mechanism for bidirectional, variable speed operation and also includes a disposable scalpel tip with infusion/irrigation orifice for communication with an intraveneous solution bag. The scalpel tip is coupled through a clutch mechanism to the motor, which may be adjusted by the control system to make single or repeated cuts in either of two rotary directions. The aspirator's most frequently needed controls are mounted on the handpiece to provide an easily operable instrument of great precision for use in eye surgery. The instrument features an electronic control circuit housed in part within a desk top or suspendable unit and in part within the handpiece.