Have you ever heard of Brain Fingers? It's a computer controller (mouse-like) that hooks to your head and it mostly reads the electromagnetic impulses from your face to control the mouse.
Apparently it works decently and has given some severely disabled people (paralyzed from the neck down) access to computers again.

Byron,

My sister works as a nurse at a revalidation (or maybe rehabilitation in English) centre where they try to give ppl with almost full function loss ( neck down, mostly motorbike accidents) some function again. I know that they use a device you have to put on your screen that has a camera and computer attached. It ‘reads’ your eyes and points the mouse where you look on the screen. Only disadvantage is that you have to put a big round red sticker between your eyes so the machine can calibrate to that. If you are (serious) interested I can ask what it is called. I played counterstrike with it once. It’s not perfect yet ( prolly has something to do with my CS skills as well lol) but it does the job fairly well.