Board Thread:Theories and Speculation/@comment-1512913-20150221101637/@comment-25549954-20150301092818

Madara didn't have eyes or Mangekyou activated when he activated his Susanoo, similarly Itachi didn't have Mangekyou Sharingan activated, so I think that eyes aren't needed at all after the initial activation of the two Mangekyou.

My theory is that Kakashi still has Susanoo as a gift from Obito, after his first activation of Mangekyou there is a change in chakra pathway that will allow him to access Susanoo.

Sasuke used Genjutsu: Rinnegan on tailed beast and they had Rinnegan reflection in their eyes, which were similar to person affected by Infinite Tsukuyomi, I believe Infinite Tsukuyomi is more like a Rinnegan Genjutsu, or may be sharingan in his eye casts Genjutsu and Rinnegan is just to cast on/control all the tailed beast.