In early drafts of the first book, Rowling included a Divination professor named Mopsus.
Richard Wheatley for the RNIB: - Blind children everywhere are delighted that they can read this book at the same time as sighted people, would you ever include a blind character in one of your Harry Potter books?
JK Rowling: Funny you should say that because at one point there was a blind character who went by the name of Mopsus, and I will let you look him up because there is a mythological connection there, but he sort of that was a very early character and he had the power of second sight, in other words he was a bit like Professor Trelawney, he was a very, very early character, this was when I was drafting Philosopher's Stone, the reason I cut him was he was too good. As the story evolved, if there was somebody who really could do divination at the time that Harry was alive, it greatly diminished the drama of the story because someone out there knew what was going to happen.
So that is why Mopsus went and I have never really replaced him, although I suppose Mad-Eye Moody, had some of Mopsus' characterisation. He has one magical eye because he lost an eye in a fight with a Death Eater, so good question. (http://www.accio-quote.org/articles/2005/0705-edinburgh-ITVcubreporters.htm)