an endoscope for eye surgery incorporates a handle having a camera and an electric motor driven lens assembly for enabling a user to focus the camera during surgery without manually adjusting the focus . the endoscope includes a probe attached by a rotatable bayonet type connector with a simple pivoting lever to release the probe from the handle . the motor drive system incorporates spring biasing to compensate for overruns of a drive nut on a lead screw when the user attempts to exceed the focal range of the lens assembly .