An illumination system for producing a spatially distributed illumination pattern for measuring the cornea of an eye and, in particular, for determining the topography of the eye. In so doing, the system facilitates distance-independent measurements. The illumination system includes an illumination unit, an optical element for collimating the illumination light and a unit for producing a spatially distributed illumination pattern in the form of a fraxicon. In particular, the illumination unit includes a plurality of illumination modules which are arranged such that each illumination module illuminates part of the fraxicon, and consequently a full-area illumination is facilitated. The system for producing a spatially distributed illumination pattern serves to determine the topography of the cornea of an eye. Here, the system is designed as a compact module, and so it can be easily combined with other measurement systems, without interfering with the beam paths thereof.