The Witcher
Nekker eyes are used as crafting components, alchemy ingredients and also as quest items. Two sets of eyes in particular are listed as quest items and as such valued at 0 and a weight of 0. They are also used to craft amethyst dust.
Associated quest
The Witcher 3: Wild Hunt
Nekker eye is an alchemy ingredient and can be dismantled into Monster eye. It is also needed to craft the following items: