Silver Eyes are objects in the world of Kill the Past which can (supposedly) grant immortality to those who replace one of their own left eye with it. However, the exact powers of the Silver Eyes are unclear and have been said to include the aforementioned immortality and youth, indirect immortality via transferring one's consciousness into another body, as well as the power to rewind time. A feature that has been show to be true is the ability to interact with the souls of dead people who cannot rest. A true Silver Eye user can also take on a dead soul's personality as an "Alter Ego" as stated in the Yuki Chapter in The 25th Ward: The Silver Case.
The eyes originate from Lospass Island, a breeding ground for a rare breed of hyenas that have the Silver Eyes; however, their eyes are not silver initially, and only become that color through a process known as "Ocular Silverization" when inserted into humans under specific circumstances. Another way for someone to gain Silver Eyes is for them to be born from those who have partial Silver Eyes or sheltered kids, as shown in the the 25th ward, when both Yotaro Osato and Yuki are naturally born with them.
The first Silver Eye found by the Ward 24 government was originally discovered to have been implanted into Kamui Uehara. During The Silver Case, the elderly politicians killed each other over the eye, with Uminosuke Hachisuka being the sole victor, putting the eye into himself and becoming immortal. After this, the ward government begins the Shelter Kids Policy, with one of their goals being Ocular Silverization, although they were never able to reach it.
- Kamui Uehara - Had a Silver Eye implanted into him on Lospass Island when he was two years old.
- Uminosuke Hachisuka - Stole Kamui's eye after killing him.
- Tokio Morishima - Stole Uminosuke's eye after his death and kept it throughout Flower, Sun, and Rain, but lost it afterwards. His right eye was then replaced with a man-made Silver Eye (see below).
- Tetsugoro Kusabi - Has a Silver Eye as Peter Bocchwinkur, but it is unclear if it's kept afterwards.
- Step Sding - The clone fitted with a bomb seen in Flower, Sun, and Rain appears to have one.
- Catherine - According to SUDA51, it has a Silver Eye in its core, although Sumio Mondo is not aware of it.
- Yotaro Osato - Appears to have two Silver Eyes.
Man-made Silver Eye
In the backstory of The 25th Ward: The Silver Case, while staying in IMM Hospital, Tokio Morishima's right eye was fitted with an artificial mechanical Silver Eye. This type has other features; most notably, he uses it as a data plug to extract information into his body, which then designates him as a "tape".
Possible Silver Eyes
A far future version of Travis Touchdown and Sylvia Christel appears in audio skits before "N.M.H" and "IYOGIN" on The Outer Rim (album). They are both depicted in astronaut suits, 120 years after their marriage and 76 years after taking a shuttle into outer space, Travis and Sylvia have apparently both "achieved immortality". Travis presents Sylvia with a music box found on a crater as a birthday gift, and N.M.H. begins. The song closes with Sylvia naming the miniature band inside the music box "The Outer Rim". In the skit before "IYOGIN", Travis and Sylvia discuss a dream Travis had in his sleep the previous night regarding his time in Tokyo. Sylvia replied that the men in black who closed the record shop were part of the UAA, although this claim makes little sense.
There is some speculation that the God-Hand and God-Killer in Killer7 are potentially related to the Silver Eyes, due to their owners having immortality and strange powers. Kevin Smith seems to have white or silver colored eyes that are said to glow in the dark, but his planned plot significance is never mentioned in the game. (Interestingly, in the flashback cutscene in the Union Hotel, his eyes are normal; this may or may not be part of his disguise.)
In a Killer7 beta trailer, an early character design for Garcian Smith is seen to have two glowing silver eyes, which he conceals under a pair of sunglasses. A beta model of Emir Parkreiner extracted from Killer7's game data shows that, at one point in his character design, his third eye was silver. Even without the his eyes being silver, all of the abilities that Emir has in Killer7 are abilities granted by the silver eyes.
It appears that Mondo Zappa's left eye glows with power when he uses his silver Ulti-Mondo form. What this means in relation to the Silver Eyes of past titles is unclear.
Kamikaze Wateru (the protagonist of Kurayami Dance) has an odd-looking eye that is drawn the same way that Silver Eyes have been drawn in past illustrations. However, his special eye is in the right socket, unlike every natural Silver Eye; other scenes show two different colored eye implants, a lighter one for the left socket and a darker one for the right socket.