After Sollux was first knocked out from the fight with Eridan, wasn't he completely blind? If so, how did he go from that to half-blind?

Okay, this is kinda difficult to explain, so there was blind sollux and a ghost sollux and when blind Sollux died the two kind of merged into a half-ghost Sollux that was blind in one eye. And then pre-retcon the ghost was sucked out to make Erisol so then he was 100% alive but entirely blind. 

We don’t actually know how that works, it probably has something to do with him having two dreamselves.