Yeah, sorry but... the whole "I have two eyes now and can ACTUALLY FULLY SEE AGAIN" being something that's supposedly hindering Slade is a little silly. It's like a blind man saying he's hindered after having his sight fully restored. It certainly isn't something that should take that much adjustment to get used to in fight, and Slade has been complaining about it for long enough now. Seriously, how can having full field of vision be throwing him off? If it's throwing him off, it should be in a good way if anything. "Hey look, I can see that attack incoming now! Cool. I think I'll dodge it."
I think it has more to with the fact that half of his mask was tinted. I think seeing clearly and bright out of one eye, and dark out the other would be irritating.