A system for determining the surface shape of the cornea of an eye by analyzing the reflection of a spatially distributed ring pattern. The system includes an element for generating a ring pattern, an illuminating unit, an image capturing unit, and a control and analyzing unit. The element for generating rings is a fresneled axicon with annular structures of different radii. Furthermore, an optical element for illuminating the entire surface of the fresneled axicon with plane waves and an optical element for separating the illuminating and detecting beam path are arranged between the illuminating unit and the fresneled axicon. Furthermore, the image capturing unit consisting of an imaging system and an image sensor is designed for a telecentric distance-independent image detection.
