What exactly is the drawback to having this thing in your head?
It seems to me that there is no reason not to simply plug it in. After all the eye can not communicate directly with the owner, and doesn't seem to be dangerous. How do i keep this item interesting and not just seem to be a bauble with flavor text?
Is there no cost or down side?
The characters in my KM campaign are all good aligned, except the NE sorcerer that took the eye for himself and immediately, without research or protection of any kind, simply plugged it into his bleeding socket.
What should  happen next? I need ideas that do not take his cool trophy away from him, but that will remind him, and others, that it is a very evil thing.
I toyed with the idea that the Occulus was lost while Vordakai was imprisoned, and now it is free. Forces that want the power it offers might now come calling for it, and so try to steal it back, buy it, or blackmail the character that owns it. Paladins might come to smash it, following a vision from opposed gods...
Suggestions?
Ideas?