From the Wiki -
"The eyes of the insane white tyrant. Even after his death, the eyes continue to put fear into the heart of anyone who looks at it.
Bring it to Brynn to obtain information.
It can be obtained as a dropped item after hitting the uninjured eye of the Giant Polar Bear 5 times with spear."
No wonder its a tricky item to drop ...
"The eyes of the insane white tyrant. Even after his death, the eyes continue to put fear into the heart of anyone who looks at it.
Bring it to Brynn to obtain information.
It can be obtained as a dropped item after hitting the uninjured eye of the Giant Polar Bear 5 times with spear."
No wonder its a tricky item to drop ...