A reduction valve designed to be attached through a gastight connector (e.g., a pin-index or bull-nosed screw thread connection) to the valve stem of a gas cylinder used to deliver intraocular gas [i.e., sulfur hexafluoride (SF6) or perfluoropropane (C3F8) used as a tamponade for retinal surgery] to lower high, variable gas pressure to a lower, constant working pressure. It can be a single or a dual stage regulator, usually of a piston or diaphragm design. It will have a safety relief valve to avoid excessive pressure due to increased ambient temperatures and usually a manometer or manometers to display the available gas reserve of a gas cylinder and the working pressure.