There are many different eye conditions that are associated with congenital nystagmus; theoretically, any bilateral visually-significant pathology present at birth or in infancy during the critical period of visual development may interfere with the development of stable fixation (1) Eventually I'll get around to discussing the finer points of nystagmus; but for now, I'm sticking to some basic study stuff.
This review is somewhat multi-disciplinary in nature. As you wrap up your reviews, one of the things I found useful was to create tons of different lists. Regardless of which test you're studying for, there are many questions that are organized differently than how one might go about learning a particular disease. As such, I started making lists of different ways to group otherwise disparate diseases that might show up as a test question, or at least help me remember a specific feature of the disease.
Truth be told, there is not very much detail that needs to be learned about embryology; after all, we've already learned embryology in medical school. At the same time, there are some key embryology concepts that are very helpful to understanding ocular disease, and may also show up on test questions. There usually seems to be at least one question that addresses embryology, and there are tons of practice questions that test your knowledge of embryology.
As you can probably tell, I'm starting to skip around a little bit while I put together these OKAP review articles. I have a fairly large list of topics to cover, but hopefully these will all be helpful pieces of information. I decided to skip to aniridia, because it is one of those conditions that seems to be very popular in practice questions.