Probably a stupid question, but as someone trying to dabble in optics, what's the difference between numerical and geometrical optics?
I'm not a career optical engineer but numerical optics is a general term for computer modeling of optics (i.e. by number-crunching), like numerical anything else. In practice that means prysm can simulate wave phenomena and aspects like diffraction, polarization, phase, and interference. Geometrical optics refers to ray-tracing by geometric methods, like in introductory physics courses.