I'd expect that virtually all lens design and analysis these days is done with optical design software like Zemax or Code V. Unfortunately, these products are priced for people and companies that make a (substantial) living working in the field. However, I have come across an optical design tool for Windows called OSLO that offers a free version with reasonable limitations. I've just downloaded it, and it comes with some relatively simple lenses in its library, like a Petzval 50mm f/1.7. It doesn't look like the easiest software to get started with, but there are some users' guides on the download page.

I'd expect that virtually all lens design and analysis these days is done with optical design software like Zemax or Code V. Unfortunately, these products are priced for people and companies that make a (substantial) living working in the field. However, I have come across an optical design tool for Windows called OSLO that offers a free version with reasonable limitations. I've just downloaded it, and it comes with some relatively simple lenses in its library, like a Petzval 50mm f/1.8. It doesn't look like the easiest software to get started with, but there are some users' guides on the download page.