What is the significance of Ed's comment on his eyes? We're clearly shown he's suffering from some sort of tunnel vision, he even orally acknowledges the change, but when he looks in the mirror his eyes are one of the few things on him that still resemble his old self. I understand the somewhat limited ability to make things look different with this animation, but what could be the significance? If they wanted to present to us that Ed was a different person, surely a proper arm and different hair should be enough.
Continuing onto the rest of the scene, and into an area that has very likely been discussed TO DEATH (oh, puns. haha) - Is the theory that the body Ed's in is Envy's original form still around? With that II can make out some other theory, in an abstract way, but if you view where Ed and Hohenheim now as the past, opposed to an alternate universe. ( I'm not sure how accepted this theory is opposed to the AU theory, so I presenting some hurried ideas before getting to the actual theory, which should work out, regardless of time- We know that the time when Christianity in Europe was prevalent [early middle ages to present] is ancient history to the HagaRen world. Holding the HagaRen world as our own world, can we regard World War I as an ancient part of the HagaRen world as well, and when Christianity fell and alchemy rose again as possibly our future? I don't know, I've never necessarily seen the HagaRen world as a separate place, especially when referencing Christianity. Arguably you can point out that we aren't exactly capable of 'magic' as HagaRen is, but that doesn't deter people from saying that yes, CCS is set in our Japan. )
BUT MOVING ON FROM THAT TO THE ACTUAL THEORY HERE :-" If we, as a group of fans, are still clinging to the Edward-is-in-Envy's-old-body theory, I present this as brief as I possibly can and with the assumption that Ed is currently in the past opposed to an alternate world. After all, the Gate shows you all the knowledge in the universe and, should it have included detours to other worlds, I feel as though that would have been mentioned before the last three episodes.
In theory, Hohenheim could have lived in London in the past. In London and the war, regardless of time, he's obviously associated with a younger man named Edward who is NOT his son. The key to pointing out that WHOEVER Edward is right now, it is not Hohenhiem's son, since the first clue to the man that this was not the Edward he knew was being referred to as "father." (Therefore if the body Ed's in now IS Envy, that makes Envy Hohenhiem's son by transmutation only and not blood.) The likelihood that this bit is mentioned is huge, but I wanted to throw it in the somehow connect the blurb about dates and this together-
It is possible that Envy is the resurrected form of the Edward Hohenhiem knew during W.W.I, the boy Ed Elric is in right now (We can call that past!Edward v. 1.0). Edward 1.0 is someone we can obviously assume died, if not prematurely and with some guilt on Hohenhiem's side. I make that jump because young death and guilt and unresolved issues lead to mistakes like Human Transmutation. Following the fact that reviving Edward 1.0 is not what Hohenhiem expected it to be (no attached soul, disgusting mess without kenja no ishi), he 'abandons' the resurrected form (Envy) and Dante, and in those 400 years between Hohenhiem meets up with Trisha. With her he has a son (the Edward we know) and has the opportunity to really 'create' the life that he tried to bring back, that past "Edward." A clean way to make up for someone that died is just putting another person in it's place! His son, conveniently named Edward, is a penance for the loss of Edward 1.0 and how un-taboo was 2.0's birth in comparison with Envy's. Hohenhiem has much less guilt with creating Edward 2.0 than he would with creating a Homunculus. What this theory then says is that Envy is a failed attempt at Edward 1.0 and Edward Elric is the version that succeeded. It's a complicated thing to write out, but it's another reaching theory on why Envy has such solid feelings of being replaced by Elric kyoudai.
That was ridiculously long-winded. I'm just dead curious about the eye thing. The kanji for episode 50 is terrfying!