For the spell, see chaos eye.
Chaos eyes will often do nothing because of their low speed, but they possess the Eye of Mutation special action, which will mutate you when used (both positive and negative mutations are possible). Get rid of them posthaste or wear something that protect from mutations if you don't want to take the risk. Alternatively you can pack up a lot of food and abuse its ability to get a lot of positive mutations.
Elona+ Changes Edit
They now spawn trained in the Firearm skill.
cardeyecreates a card of chaos eye.
figureeyecreates a figurine of chaos eye.
The sprite number for the chaos eye is 207, with a color modifier of 8 (blue).