Disclosed is a system and device for observation of an eye (E) comprising a light source (LSo) for illuminating the eye. Further, the system includes a diffraction grating as an optical relay (OR) for receiving the light reflected from the eye and for deflecting it towards a light sensor (LSe). The incident light ray (r inc) intersects the optical relay at an incidence angle (alphajnc) with the normal (n_OR) to the optical relay in an incidence plane (Pl_inc) formed by the incident light ray (r_inc) and the normal (n_OR). The deflected light ray (r def) forms a deflection angle (alpha def) with the normal (n_OR) in a deflection plane (Pl def) formed by the deflected light ray (r_def) and the normal (n_OR). The optical relay is positioned such that the incidence and the deflection angle and/or the incidence plane and the deflection plane are different from each other.
