Vengeful Eyes are a miscellaneous crafting material in Diablo III, they can be combined with other demonic body parts to create a ring of incredible power.
It has an Item Level of 63 and requires a character level of 1. They be can stacked up to a maximum of 100.
"The baleful gaze of this viscous orb is quite unsettling. It waits for... something."
Acquisition
The Vengeful Eye drops from Uber Siegebreaker or Zoltun Kulle after using the Infernal Machine at level 60-69. It is account bound.