Board Thread:Naruto Discussions/@comment-26993711-20170603214204/@comment-734582-20170605075201

Kakashisologod1 wrote: He definitely could use amaterasu and tsukuyomi more than twice. In a row, i meant. He used Tsukuyome on Kakashi, then Sasuke. He uses Amaterasu to escape Jiraiya while Kisame calls him out on not overusing his eyes. In the fight against Sasuke he uses Tsukuyome once and Amaterasu twice.

Itachi gives us data on safe use limits (twice per eye before serious downsides set in), Sasuke gives us an overall limit (Not clear how Susanoo factors into this regarding eye strain) of a dozen or so techniques, plus some unknown Susanoo time. Though Itachi uses a full susanoo once (meaning he did fully develop it), Sasuke was fighting with Susanoo for extended periods of time on several occasions. Also his eyesight wasn't fully gone like Itachi's, but it was quickly getting bad.