The Eyeless are ancient, mysterious maegfolc, more widely known in myth than fact. With their grotesque build and their crude yet functional limbs, they vaguely resemble constructs, though their origins and purpose are unknown. They know neither hunger nor fatigue, making them singularly relentless foes.
Popularly, Eyeless are said to serve Ondra by seeing old or dangerous things forgotten. The peoples of the White March describe them as bogeymen that stalk old roads and secluded places. Parents warn their children not to forget their chores lest the Eyeless see them "forgotten," and people who lose something traditionally thank Ondra that the Eyeless did not come for them, too.
You first encounter the Eyeless at the end of The Iron Flail. They are incredibly powerful vessels with a long list of immunities and set the tone for the rest of the encounters. They are vulnerable to Stasis Shell and other high level immobilizing abilities and spells, and can be knocked prone, which is about the only major vulnerability they have.