Eyes of the Master
From Multiversal Omnipedia
The Eyes of the Master, also known as tracer orbs, were tracking devices shaped like eyeballs and implanted in the hands of the children who were enslaved by Gilramos Libkath. The Eyes of the Master acted as miniature cameras, capable of sending detailed visual information back to Libkath. They would also secrete a deadly poison into the body should the child try to escape.