I originally posted this in the Dawnguard section, but think I might get better response here. This seems to be a fairly complex question, after thinking about it for a bit. I mean, Serana's eyes change, (to what???) and the player's eyes change. I assume that this is controlled via scripting, but the script has to get the image files from somewhere, yes? So where / what are they? Can they be used on another NPC? For instance, I'd love to put Serana's post-vampiric eyes into Eola's head. Imagine Eola with glow-in-the-dark eyes...