Madara used Susanoo without eyes, eh? How?

[Shadow Phantasm]

Retcom most likely.

 

[Shadow Phantasm]

Retcom most likely.

 

[Inert Brian]

Itachi had Susano'o activated after his sharingan was gone (or as others put it he was near complete blindness).

Susano'o was confirmed to put a strain on the BODY not eyes specifically. Sasuke's vision got affected at samurai bridge because his entire body (including eyes) were being strained, activating Susano'o requires concentration (confirmed when DSM Kabuto used Hakugeki), Sasuke lost concentration when he was hit with a wave of pain.

To unlock double MS, you need the special chakra in the optic nerve to unlock/release from the brain. Therefore once you have the special chakra unlocked/released Susano'o can be used. + as others have said, Susano'o doesn't directly require the eyes.

Don't call it an asspull just because you failed to put together multiple pieces of evidence (your argument was already lost when Itachi did it blind already!).

 

[SkyGodHorus]

His eyes were resonating with the gedo rods contained in his body, people. Stop making it harder to comprehend than is necessary lols.