A gas mixing system for providing mixed gas for intraocular injection, the gas mixing system comprising: first and second pressure regulators (20, 22), each having a regulator input and a regulator output and each being electronically controllable via a respective regulator control input; the regulator inputs of the first and second pressure regulators having fluidic connections with first and second gas supply inputs, respectively; first and second fixed-volume chambers (24 26) having their interior volumes fluidically connected to the regulator outputs of the first and second pressure regulators, respectively; first and second pressure transducers (28, 30) fluidically connected to the interior volumes of the first and second fixed-volume chambers, respectively; first and second shut-off valves (32, 34), each having a valve input and a valve output, wherein the first and second shut-off valves are fluidically connected to the interior volumes of the first and second fixed-volume chambers, respectively, via the first and second valve inputs, respectively, and wherein each of the first and second shut-off valves is electrically controllable via a respective valve control input; a first bleed valve having a valve input and a valve output, the valve input being fluidically connected to the interior volume of the first fixed-volume chamber and the valve output being connected to an external environment, the first bleed valve being electrically controllable via a respective valve control input; a third fixed-volume chamber having its interior volume fluidically connected to the valve output of the first shut-off valve and to the valve output of the second shut-off valve; a third pressure transducer fluidically connected to the interior volume of the third fixed-volume chamber; a third shut-off valve having a valve input fluidically connected to the interior volume of the third fixed-volume chamber and having a valve output, the third shut-off valve being electrically controllable via a valve control input for the third shut-off valve; a second bleed valve having a valve input and a valve output, the valve input of the second bleed valve being fluidically connected to the interior volume of the third fixed-volume chamber and the valve output of the third bleed valve being connected to the external environment, the second bleed valve being electrically controllable via a respective valve control input; and a connector in fluid connection with the valve output of the third shut-off valve, the connector being configured for removably connecting to a filter and intraocular syringe. first and second pressure regulators (20, 22), each having a regulator input and a regulator output and each being electronically controllable via a respective regulator control input; the regulator inputs of the first and second pressure regulators having fluidic connections with first and second gas supply inputs, respectively; first and second fixed-volume chambers (24 26) having their interior volumes fluidically connected to the regulator outputs of the first and second pressure regulators, respectively; first and second pressure transducers (28, 30) fluidically connected to the interior volumes of the first and second fixed-volume chambers, respectively; first and second shut-off valves (32, 34), each having a valve input and a valve output, wherein the first and second shut-off valves are fluidically connected to the interior volumes of the first and second fixed-volume chambers, respectively, via the first and second valve inputs, respectively, and wherein each of the first and second shut-off valves is electrically controllable via a respective valve control input; a first bleed valve having a valve input and a valve output, the valve input being fluidically connected to the interior volume of the first fixed-volume chamber and the valve output being connected to an external environment, the first bleed valve being electrically controllable via a respective valve control input; a third fixed-volume chamber having its interior volume fluidically connected to the valve output of the first shut-off valve and to the valve output of the second shut-off valve; a third pressure transducer fluidically connected to the interior volume of the third fixed-volume chamber; a third shut-off valve having a valve input fluidically connected to the interior volume of the third fixed-volume chamber and having a valve output, the third shut-off valve being electrically controllable via a valve control input for the third shut-off valve; a second bleed valve having a valve input and a valve output, the valve input of the second bleed valve being fluidically connected to the interior volume of the third fixed-volume chamber and the valve output of the third bleed valve being connected to the external environment, the second bleed valve being electrically controllable via a respective valve control input; and a connector in fluid connection with the valve output of the third shut-off valve, the connector being configured for removably connecting to a filter and intraocular syringe.