My next idea involves a creature whose eyes are useful for certain alchemical recipes. At least for potions they are.
Hopefully they're just what we need for this and there aren't any further... miscalculations. Although, I don't entirely recall seeing them on the recipe's ingredient list... but my memory isn't exactly as good as it used to be.
Oh, you caught me rambling. How about you get those eyes and I'll start making the preparations for them.