A system for assisting a surgeon performing intraocular surgery on an eye of a medical patient includes a robotic arm and a tool assembly at a working end of the robotic arm. The tool assembly can include a proximal end mounted to the robotic arm's working end, a distal end, and a narrow elongate support member extending between the tool assembly's proximal and distal ends. A motion controller is operable to move the robotic arm to extend the distal end and at least a portion of the support member through an incision site in a surface of the patient's eye, thereby to locate a visualization element at the distal end of the tool member at a position inside the patient's eye.