Determination of biometric parameters of an eye, in which the optical axis of the biometric measurement system is aligned to the optical axis of an eye. The device includes an interferometry measuring arrangement having a measurement light source and a measurement sensor, a fixation light source for capturing the eye with the reflexes that arise, an image sensor, and lens for detecting volume scattered light and an analysis unit for determining the angular deviation of the optical axis of the eye from the optical axis of the biometric measurement system. The analysis unit compares determined angular deviation to a predefined tolerance and, laterally displaces fixation marks on the basis of the calculated angular deviation, or of initiating the biometric measurement.