# How is raytracing performed in anisotropic media?

I wish to determine the path taken by a light ray between two points, $$a$$ and $$b$$, through an anisotropic medium. More specifically, this medium has an index of refraction which varies as an exponential function of depth.

I'm not terribly familiar with the methods of raytracing in computer graphics, however I understand that such problems are within the domain of raytracing. Algorithmically, how might such a path be determined (ideally, more efficiently than writing and solving systems of differential equations)?