Advanced geometric optics as traditionally presented uses the approach of Conrady. The subject can be made easier to teach and learn through the use of two powerful tools: matrix-based paraxial optics and computer-based non-paraxial analysis and design. Programs which handle many different kinds of problems are discussed and misunderstandings concerning the definitions of the point aberrations are corrected.
Allen Nussbaum, Allen Nussbaum,
"Modernizing the teaching of advanced geometric optics", Proc. SPIE 3190, Fifth International Topical Meeting on Education and Training in Optics, (8 December 1997); doi: 10.1117/12.294407; https://doi.org/10.1117/12.294407