The present invention is directed to a solution for measuring geometric parameters in the eye which are required for calculating the refractive power of intraocular lenses. The device according to the invention for axial length measurement which acquires axial length, anterior corneal radii, anterior chamber depth, and other parameters in the anterior eye segment includes a control unit, a first measuring device for determining axial length, and an additional measuring device which acquires a plurality of structures in the anterior segment (such as the cornea, anterior chamber, and lens) and which has at least one illumination unit and at least one image recording unit. By determining additional partial-distance parameters of the anterior eye segments, the IOL can be calculated with high precision even after refractive surgery in which the natural relationship between the radii of the anterior and posterior corneal surfaces is extensively altered by corneal surgery.