Itachi gave Shisui's eye to Naruto during the Itachi Pursuit arc. This eye was stuffed in the form of a crow, when Naruto was under Itachi's genjutsu.
See below image from Chapter 403, when Naruto is sitting in his room and having a flashback about his encounter with Itachi.
Eight Konoha shinobi went on a mission to find, and if possible capture, Itachi, since they hoped it would give some clues to Sasuke's whereabouts. At the same time, Sasuke with his Team Taka started moving to Itachi's hideout because he wanted to kill Itachi. Itachi knew his end was near, and it was part of his plan to die at Sasuke's hands.
Before he died, he wanted to talk to Naruto, presumably because he was still worried about what Sasuke would do after his death. He sent a shadow clone to talk to Naruto. This clone encountered one of the thousands of shadow clones that Naruto previously created to search for Sasuke.
Naruto was angered on seeing Itachi and unwilling to listen to anything Itachi had to say, so Itachi was forced to cast a genjutsu to make him listen. On hearing Naruto's determination to save Sasuke at all costs, Itachi decided to give him Shisui's eye, which would help him in case he had to take Sasuke back by force.