[Endoperez]

Aim and Eagle Eyes are spells that grant the same benefit (+4 precision), so they don't stack with each other. Eye of aiming may either 1) cause one of these spells to be cast at the user or 2) grant precision directly. 1) doesn't stack, 2) stacks. I don't know how Eye of Aiming works, but the manual lists if it acts as a spell IIRC.