CENTRING APPARATUS AND METHOD FOR DETERMINING OPTICAL CENTRING PARAMETERS OF A SPECTACLE WEARER

The invention relates to a centring apparatus (10) of a spectacle wearer (30), having a fixation target (40) which generates a two-dimensionally extended light field at a measurement location for illuminating at least one eye of the spectacle wearer (30). A measuring device is used to ascertain at least one measurement position of the at least one eye of the spectacle wearer (30) when viewing the light field generated by the fixation target (40). A correction device comprises deviation information about a deviation of the light field actually generated at the measurement location by the fixation target (40) from a setpoint light field predetermined at the measurement location. The correction device corrects the ascertained measurement position of the at least one eye when viewing the light field actually generated at the measurement location, taking into account the deviation information, to a setpoint position of the at least one eye, which the at least one eye would likely assume at the measurement location if it were to view the predetermined setpoint light field there. A parameter calculation device ascertains at least one of the optical centring parameters to be determined on the basis of the ascertained setpoint position of the at least one eye.