What I'm doing (for work) -
Do you know the difference between a retinal scan and iris recognition? A retinal scan reads the pattern of blood vessels inside your eye and works like this. Iris recognition measures the shape and uniqueness of your iris and allows you to do things like this. I'm working with a company that creates iris identification technology, which is awesomely geeky, but I now need to try to explain their products graphically in a way that somehow looks like this and not like this.