The invention relates to a device for eye surgery comprising a vacuum pump arrangement (44, 46) for producing a vacuum for fixing a suction ring (24) to an eye, an evacuation path system (48) for transferring the vacuum to an interface connection (18) that enables the detachable connection of a suction ring apparatus (14) comprising the suction ring, and a control unit (40) for controlling the vacuum pump arrangement. According to the invention, the device comprises pressure measuring components (52, 54) for measuring at least the vacuum pressure, said control unit being designed to determine a differential pressure between the measured vacuum pressure and an atmospheric pressure. Preferably, the vacuum pump arrangement is operated under a test operation run, with maximum pump power, when the suction ring apparatus is not connected, in order to determine the best possible relative partial vacuum that can be achieved in the evacuation path system (48). In this way, it can always be determined whether the obtainable relative partial vacuum is sufficient, even when the eye surgery device is used at varying altitudes and under variable weather conditions (low pressure, high pressure).
