(You know, as eyeballs of the Absolute, doing stuff in front of them seems of little consequence. Call a few nearby randos to a fight? BD. At some point, you'd expect it to dispatch a platoon to getcha!)
When you first encounter one, it's implied by several companions that someone far away is using them to see what's happening. Suggesting Ketheric or Gortash are the ones using them, either personally or having some mook(s) watch for things.
They really should have more of a consequence than being basically just a crappier version of a random goblin and a drum... At the very least, higher level Absolutists should react if you made a scene in front of one. If not, just make it some random person who's acting as a sentry rather than some strange magical eye thing...
Floating over water, bad! Floating over lava, A-Ok!
It's all to do with kill planes.
Unpathable areas are made of kill planes that will instantly kill entities that pass through them. (It's also why it's annoying as sin to try and actually throw a target into these areas because it will constantly be seen as an invalid location)
The lava near the duergar is pathable (As it seems to be an intended mechanic that you can get pushed in and then have a chance to jump back out) so doesn't instantly kill the eyes.
The exception is the little area that looks like a large crucible (Next to the large anvil and that dwarf lass with a crossbow who goes invisible), you can toss the eye down there and it dies (And sometimes isn't considered an act of aggression because it's too far away to be seen)
For the most part, these unpathable areas make a lot of sense. Such as deep chasms, edges of cliffs or raging rivers. But in some cases it can be a bit weird, such as the water being an insta-kill zone when it's just a calm lake.
One of the strangest ones, is that little bridge next to Minthara in the Goblin Camp. From appearances it's supposed to be some sort of deep chasm... But if you toss a goblin in there their body just sits there a couple of feet down. (Though the entire goblin camp has issues with its chasms... The large chasm near Priestess Gut's room that the goblin in the cage is hanging over is also strange as you can still see goblins thrown in there because it's not particularly deep it's just coloured black to look that way)
