In the late seventies, a theory for the aberrations of optical systems that are not symmetric was developed. This particular approach had the advantage of building directly on an optical designer's insight into the conventional Seidel aberrations. In today's high performance computing environment, it is now possible to use aberration field visualization tools to optimize nonsymmetric systems, without a working knowledge of the underlying vector aberration theory. The application of these methods to current problems in astronomical instrumentation will be demonstrated.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.