Disclosed is an anastigmatic anamorphic lens unit for processing images, particularly multidimensional images, as they are generated and evaluated, for example in connection with spatially resolved spectroscopy. The lens unit has a high anamorphic factor and comprises several lens subassemblies, a positive refractive subassembly (a) comprising at least one rotationally symmetrical lens or lens group being disposed on the lens side in order to reduce the field angle. A central optical subassembly (b) is disposed behind the positive refractive subassembly (a) in the beam path for beam divergence in one or more directions perpendicular to the optical axis, while maintaining small field angles, wherein the central optical subassembly (b) comprises at least one anamorphically distorting element and one or more rotationally symmetrical lenses or lens groups. An additional optical subassembly (c) for narrowing and enlarging the aperture on the axes in which the beam is diverged is disposed on the image side, wherein this optical subassembly (c) located on the image side alternately comprises at least one anamorphically distorting element and at least one rotationally symmetrical lens.