I went to locate a stronghold on my survival, single player, world but the eye of ender lead me to, well, nothing. I re-created the world in creative and ithere it was, right where I was digging a cavern to try and find it! in the attatched screenshots, you will see what the same area loocs like in survival, as wel as creative. I've marked the spot the eye keeps going to in both modes, I also may have punched out some blocks in creative to clear the area lol.
If you wish to check it out for your self, here is the seed: 2614790235376886615