A rod lens comprises a tubular body having a first end, a second end, a length and a diameter, a first optically transparent closing element, tightly sealing the first end of the tubular body, a second optical transparent closing element, tightly sealing the second end of the body. The rod lens further comprises n further optical elements being positioned within the tubular body defining n+1 chambers in the tubular body, with n being an integer >0, and n+1 optical fluids being positioned in the n+1 chambers, with each of the n+1 optical fluids being positioned in one of the n+1 chambers, whereby at least one of the n+1 optical fluids having a refractive index different from the other n+1 optical fluids.