1. A method for determining distances in the anterior ocular segment, preferably a pupil diameter and/or an iris diameter, wherein the image of at least part of an eye is captured and digitized using an image-capturing unit and an arrangement for illumination of the eye, and, on the basis of said digitized image, a centroid analysis and a center determination is effected as a rough determination via an intensity threshold analysis, in particular with respect to a position of the pupil, and a fine detection of the position of pupil edges and/or of iris edges is effected on the basis of such rough determination.