The Third Eye is an ability in the world of killer7. It originally belonged to Dimitri Nightmare, but when Emir Parkreiner was born it passed on to him. The Third Eye is why Harman Smith took an interest in Emir. After becoming Garcian Smith, however, Emir's third eye closes, and begins to open again as he approaches the truth - in this respect, the Third Eye can be seen as a metaphor for Garcian's self-awareness of his identity and past.
The specifics of the Third Eye's powers are not quite clear, but it's possible that it allows one to take control of others' powers, and thus the reason why Emir managed to hijack Harman's Multifoliate Personae Phenomenon and become the dominant personality.
The Third Eye informs a lot of the game's motifs, such as the health bar, the final Odd Engraving and the name "Deltahead".
- A special eye with mysterious powers being focal to the game's backstory parallels the function of the Silver Eyes in The Silver Case's structure.
- Yuriko Tsukigime from Short Peace: Ranko Tsukigime's Longest Day also has a third eye, although it seems to serve a very different purpose than the one in killer7.