Is software available to analyze optical designs of telescopes?

Does software exist, preferably downloadable from the Internet, that I can use to analyze original optical designs of telescopes?

Yes. The easiest way to find what’s out there is with a fine-tuned Google search. Right now, if you enter “optical design software” as the search terms, you get a few million Web pages. But near the top of the hit list you'll find Northern Lights Optical’s convenient tally of such software at The software options range from free demonstration versions to powerful commercial applications.

— Stuart J. Goldman