Abstract: A computer system displays a first object that includes at least a first portion of the first object and a second portion of the first object and detects a first gaze input that meets first criteria, wherein the first criteria require that the first gaze input is directed to the first portion of the first object in order for the first criteria to be met. In response, the computer system displays a first control element that corresponds to a first operation associated with the first object, wherein the first control element was not displayed prior to detecting that the first gaze input met the first criteria, and detects a first user input directed to the first control element. In response to detecting the first user input directed to the first control element, the computer system performs the first operation with respect to the first object.

Abstract: A fluid actuated, valveless sanding tool is disclosed which comprises a housing containing a cylinder, a double-ended piston mounted for reciprocal movement within the cylinder, a mounting plate to which an abrasive tool can be attached, and a double rack and pinion connecting means reciprocally driving the mounting plate. A fluid supply system delivers pressurized fluid to a central portion of the bore and a vent system permits venting of the ends of the cylinder. The piston has two end seals and three internal, main seals which maintain a fluid tight relationship with the inner cylinder wall. Two internal passages in the piston are in communication with the annular areas between the three main seals and the respective ends of the piston.