First sight

First sight is a great concept put forth in Terry Pratchett's books. Basically the idea is you see what's actually there versus what you think/want to be there. So when magickal things happen and most people can't see them because they don't believe in magick the person with first sight sees everything as it is. It also explains why eye witness accounts of things are so frequently off. I mean other then the trauma usually associated with needing an eye witness.