  In this paper, we prove that lightlike geodesics of a pseudo-Finsler manifold
and its focal points are preserved up to reparametrization by anisotropic
conformal changes, using the Chern connection and the anisotropic calculus and
the fact that geodesics are critical points of the energy functional and Jacobi
fields, the kernel of its index form. This result has applications to the study
of Finsler spacetimes.
