Improved eye surface topographer

A system for determining the topography of a diffusely reflecting curved surface, comprising two telecentric projection branches that independently project fringe images of a Ronchi grating on the diffusely reflecting curved surface and a viewing branch of which the optical system projects an image of the diffusely reflecting curved surface on its camera target, further comprising a computer that receives the fringe images recorded by the camera target and calculates the topography of the diffusely reflecting curved surface, wherein:

• the projection sources in the projection branches are semiconductor diodes that emit light of a wavelength between 400 and 500 nm;
• the optical axes of the projection branches and the viewing branch lie in one plane;
• the angles between the axes of the projection branches and the viewing branch are equal and opposite and the three axes intersect in one point;
• the optical system of the viewing branch is telecentric in its object space and its image space and transmits light of a wavelength longer than 500 nm;
• and
• a focusing tool is included in the system, the focusing tool comprising two narrow beams focused from different angles on the surface to be measured.