I am trying to teach myself optics out of the text by Sears, with some looks at Optics and Vision and a few other texts. I'm trying all the problems in Sears, and the answers to the odd problems are in the back. Unfortunately, I am getting a good fraction of the problems wrong. Sometimes it is just a simple error that I work out, but other times I go over it multiple times and I can't see anything that I did wrong. I don't feel that I am building a good intuition for the subject, either. I actually teach physics 2 and have to fumble every year on the optical instruments chapter; despite a lot of study over the past six weeks, I still don't feel that I could get more than 80-90% of the freshman problems right. There always seems to be one more assumption that I am supposed to know to make, and sometimes it seems that there are multiple approaches that seem valid but give different answers. I am trying to learn this well. So what textbooks or other sources of problems would people recommend, that have answers available, for learning optics properly? After ten chapters in one text, and seeing another text look almost completely different, I am starting to get discouraged. One or two questions I could post here; but I seem to have many. Thanks in advance.