Personally, I think Sasuke knew Madara was watching. Sasuke isn't showing his trump cards for a reason. He knows he's going to have to face Madara some day.
Orochimaru said that sasuke's genjutsu was just like Itachi's.
http://www.mangareader.net/93-350-11...apter-345.html There's no reason why he would not have been able to make a valid comparison. Being a sanin, he should be a credible witness to both of their genjutsus.
Sasuke is no idiot, he's got to know that Madara just wants his eyes.
http://www.mangareader.net/93-35269-...apter-467.html He should have figured out by now that every time he's in battle, Madara lets him push his eyes to new limits, then saves him before he is killed. I suspect that as soon as Sasuke reaches a plateau that Madara is going to come looking for his new set of eyes. I do realize that Madara has already taken his old eyes, which are blind. But with Itatchi's eyes, his sight is restored. Those EMS eyes are what he's truely after.
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