I was thinking, if Misa's life span has been halved and then halved again, it must be really short. For the sake of the argument lets say her original life span was 100. Then after trading half her life for the shinigami eyes twice, it must've been reduced to 25. How old is Misa now anyway? around 23-ish? So then that would mean that Misa should die in the very near future. But then again this is if her original life span was 100. Most people dont live that long though. So shouldn't Misa technically be dead already? Unless her actual life span is around or more than 100. Either way she only has a few more years to live at most.
Or have i got this whole shinigami eyes/life span trade thing all wrong? o_O
I apologize in advance if this has been posted or discussed before =)