Board Thread:Theories and Speculation/@comment-36512555-20200101053037/@comment-32685487-20200408204052

I just explained to you, he said with his Sharingan he could see that Sasuke was out of chakra, Sasuke was indeed NOT out of chakra and Itachi couldn't tell otherwise. Sasuke had enough to initiate Kirin. Itachi's eyesight by that moment was bad enough that he couldn't even see Sasuke or Sasuke's chakra from that distance. In fact just activating Susanoo completely blinded Itachi.

https://1.bp.blogspot.com/-L9IfWopO_AU/XeZTPu9MlgI/AAAAAAAAKjc/mp-cmQ9ubRMHXPLQ55byspWWcC1cDsx2ACLcBGAsYHQ/s1600/016.webp

Itachi COULD NOT see Sasuke let alone his chakra due to how bad his eyesight was, he THOUGHT he could but he ended up wrong. Itachi could only notice the extreme brightness change in lighting. Again at this point his eyesight was so bad that just activating Susanoo blinded him fully. Itachi reacted to Kirin within 1/1000th of a second(launch to strike) that's a legitimate feat whether anybody likes it or not.