Board Thread:Naruto Discussions/@comment-25531508-20141007153206/@comment-1512913-20141007172101

No idea. But Ao had a seal on his Byakugan and Hyuga themselves do. Maybe he sealed his third eye to resist temptation of Infinite Tsukuyomi, or just in case Indra would attempt to use Sharingan on him, forcing him to use it :P