The theory of computing the contributions of each refractive surface of the optical system to total aberrations was applied to the human eye model for the first time. To compute the contributions of each refractive surface and the variation of the aberrations after each surface, a ray tracing program has been written in C language. For the first time the contributions of each refractive surface to the coma were computed. And the coma aberrations caused by cornea and that caused by lens can be compensated for each other. Cornea anterior surface contributes most to the eye aberrations and the posterior surface of the lens played the second role which can give good information to the design of artificial crystalline lens.