Evolution of the polarization state of light transmitted through an optically active medium follows from the Maxwell theory of electromagnetism. The theory can be reduced to the study of a Schrödinger-like equation for two levels representing the right-and left-circular polarizations, respectively. Using quantum mechanical techniques, we show that the Stokes parameters should exhibit tunneling in the anisotropic nonlinear medium-a phenomenon similar to quantum tunneling-provided the nonlinear parameter be large enough. In order to recover the quantum results in the classical framework, one has to consider additional fluctuations of the initial parameters, since the classical problem has no fundamental fluctuations. Indeed, even for small fluctuations, the polarization state may exhibit chaotic tunneling across classically forbidden regions. This is exemplified through polarization tunneling in a nonlinear transparent medium submitted to constant Kerr effect and modulated nonlinear parameter.