Board Thread:Theories and Speculation/@comment-890307-20161205161301/@comment-25122992-20161219161921

Lorenzo VonMT wrote: The swapping theory is a big assumption as well, its an even bigger assumption because you have to speculate the reason why the eye patterns are merged, you then have to speculate how the EMS abilities are stronger than the MS abilities, then you have to speculate how swapping two sets of blind eyes will automatically cure the blindness. There are too many assumptions with this theory, with the merging theory, you only have to make one assumption: fusion, and it answers all those questions above. No, it's not an assumtion, but already a fact. Itachi literally said that Madara became a new wielder of Izuna's (not Madara's + Izuna's) eyes. Since the previous panels depicted Madara takind out Izuna's eyes (which didn't happen that way, but doesn't really matter in this case), it's kinda clear how they were passed. Thanks to the interaction between the new eyes and the new owner, it became a new doujutsu (EMS), with the light never fading away and the abilities getting stronger. It was the main explanation of the EMS made by Itachi, and there's no more info in the series which can explain it better. And you're speculating on the whole "merging process" that never took place or wasn't ever mentioned in the first place, despite us receving a lot of info about genetic experiments in the series. Besides, by your logic, you have to make the assumptions how the merging of two pairs of blind/half-blind eyes should help in restoring the eyesight. Some minor assumptions regarding the details are better than a one big assumption that has no facts proving it.

And no, the situation isn't that different from other doujutsu transplantation. Since it's literally a transplantation, it's all the same process, just the consequences are different, since the strong blood ties between the tralsplantator and transplantee ensure that the transplanted eyes will be accepted as if they were the original eyes, while the eyes transplanted to a completely foreign wielder already have some drawbacks (consuming more chakra during its use and prevening Sharingan from being deactivated).