A corneal topographer is described, the topographer comprising: -a multi-colored stimulator comprising a plurality of light sources arranged to form a multicolored pattern of source points for projecting a plurality of light rays onto a surface of an object of interest, such as a cornea； -a lens-camera system arranged to receiving a respective plurality of reflected light rays reflected of the surface of the object of interest, thereby forming a pattern of image points； -a computational unit for determining a mathematical model of the surface； the computation unit comprising a memory unit provided with color pattern information based on the multicolored pattern of source points of the stimulator； the computational unit being arranged to, for each of the plurality of reflected light rays, establishing a one-to-one correspondence between a source point and an image point based on the color pattern information； the computational unit further being arranged to construct, based on positions of the image points and positions of the corresponding source points, the mathematical model of the surface.
