So the star made it so hard to see that the species began to evolve to keep up to speed. They drew from the force, while the eyes they had, over time, began to regress until they no longer functioned.
To make it all work, i'm going to go ahead and say there's something there, but whatever's there doesn't work, and may not look anything like what it used to.
I'm going with pic #2, the way the flesh looks is like it's molding over into indentations on the face. I see Nihilus as a base creature in the shape of a man. I'd expect him to see through the force since it's consumed him almost completely. (So his eyes wouldn't function - need to function)
That in mind, he probably didn't even know Visas didn't have eyes, and gouged the area as best as his evil animal self could - tearing the flesh. *cries for Visas*
'Course, i'm going to go with the semi-fairy tale ending and say Visas eye area (as Kreia mentioned) was healed up by nice Mr.Exile, or herself after she went nice-nice light side. And by healed, I mean the flesh. Not grew herself some working eyeballs.
I'm going to take a few dozen cracks at more Visas fanart - I'm already working on one, all cg'ed (not THAT pro) in photoshop. The others i'll sketch in, do some easier coloring, and perhaps post it on here for others to improve upon, or as is.
^ First post. - That's what looking up google images for Visas gets me. >.<
