Board Thread:Theories and Speculation/@comment-31732419-20170413134103/@comment-5509055-20170502232733

Acutualy, Madara was dying at the time & wouldn't have had enough chakra to keep his rinnegan or sharingan active. As it has been shown, the origin activater of a doujutsu can turn on & shut off their doujutsu, & the doujutsu automaticly shuts off if they don't have enough chakra.