Current methods to measure intraocular scattering provide information on the total scattered light, which consists of the combined contributions originating from different ocular structures. In this work, we propose a technique for the objective and independent assessment of scattering caused by the cornea and the lens based on the analysis of the contrast of the third and fourth Purkinje images. The technique is preliminarily validated first by using artificial eyes with different levels of corneal and lens scattering; second, it is validated in eyes wearing customized contact lenses to simulate corneal scattering and eyes with nuclear cataracts. Finally, it is tested on a larger population of eyes with cataracts and corneal disorders to prove its clinical usefulness.