Quoting edawg

@ Almighty wood: although I agree with you in theory on the Izuna scenerios; there is one you left out. What if Madara and Izuna exchanged eyes? Unless Madara's eyes were sealed this is a possibility.
This is only speculation of course. It seems odd that he played such a major role in creating Madara then he died fighting blind.
I remember one issue or anime where someone mentioned that the Uchiha eye swapping/stealing was something they were killing each other over and was nothing rare or unusual (dont quote me on that).
If he did give them up willingly (and no exchange) one would assume Madara would try to protect him in his disabled state. If they were taken by force and he continued to live on one would assume his clan/village members would take extra effort to protect him (unless of course he took that decision away from them).
To anyone saying it can't be Itachi's dad Fugaku..well no one actually saw Itachi kill him. Sasuke saw him standing over the bodies of his parents, but Itachi also put him under a Genjutsu with Tsukuyomi and he lost some of his memory or had his memory altered a bit. So that is still a possibility.
And if anyone is going off of hair style. Then by that logic only a few would fit. The only ones I can think of with that type of style are Obito (ruled out due to numerous factors), Shisui (body still unaccounted for), Izuna (presumed dead if you believe the stories), Kagami Uchiha who fits into several categories for this Madara charater (except unknown motivation). However, their were scenes where Madara had longer hair, so that puts more people into the pot.
One thing Madara said to Kabuto about Nagato's Eyes were they belonged to him. I imagine he found a way to breed people with those traits in order to get those eyes or they indeed actually belonged to him (if that's the case then it may not be an Uchiha at all). Unless he knows how to clone eyes then of course he would never run out.

Sorry I wanted to think about this when I read it, and kind of missed it until now.

After considering it, I don't see this as that likely a scenario, after all Madara was blind when he took Izuna's eyes, burned up eyes regenerating doesn't sound quite right. If it was as simple as just switching them with each other, I think that would be what all brothers would do out of habit.

Ok to throw in my two cents. They mentioned before that the Rinnegan always had to have a host, so by seeing Nagato as a young boy with the eyes would mean that Madara had died around the time he received them. So IF Tobi is a clone, then why wouldn't he possess the eyes instead being that Madara would have had to make said clone before death and would have passed his eyes on. Now I also have noticed and like the points people have brought up about his eye never changing, so to me that clearly means its an implant. Another reason I doubt it is a clone is the fact that Nagato at one point agreed to help him, I don't think he would be submissive to a clones will instead of taking the power for himself, which I feel he could have done.

I also have a problem thinking that Nagato would be used to revive Madara's body anyway. If Nagato could revive anyone from any point in time, why wouldn't he sacrifice himself to revive his friend instead of a stranger. I think that is because his revival only works on recently killed... or else there would have been a lot of revived people from the Konoha cemetery >.>

Though we were told Obito's other eye was crushed, I dont recall anyone ever saying that when they buried him the eye was completely destroyed 100% so perhaps the reason he has similar abilities to Kakashi is simply due to implanting the second eye (Obito's) into himself to either pose as a Uchiha or to simply get his powers.

Read Manga Online for FREE! At http://www.de liciousmanga.com