The eikonal equation as derived by Sommerfeld and Runge has been extended to include the case of moving media under the condition where (v/c) ≪ 1 (v is the velocity of the medium, c is the speed of light in vacuum). Using the Hamilton Jacobi formalism, the equivalent system of linear equations was determined which can be used for ray tracing. An exmple of a moving medium where the index of refraction is a function of one of the coordinates has been considered.