Anime Eyes Multiplied
Generally, the word eyes signify that there are two (somewhat symmetrical in nature) orbs that allow us the sense to see. However, sometimes, especially in Anime, eyes can pertain to more than just two.
There are various reasons for this third eye (symbolic for evil and psychics), simply because they are not human, transform and gain lots of eyes, or other alignments later caused by something else. Characters with multiple eyes most of the time have an advantage for their use while other characters may have none at all. It depends on the design of the creator or author to determine what characteristics regarding sight a character has. Creating a character with this phenomenon is subjective and the characters mentioned today reflect that anomaly.
During the Yu-Gi-Oh Duelist Kingdom Arc, there was a level-one dark fusion monster by the name of the Thousand-Eyes Restrict. Also, Thousand-Eyes Restrict’s eyes have tremendous hypnotizing potential and as such making it hard to potentially maneuver around them. This monster is rightly named for its thousand eyes which caused a huge headache for Yami in his duel with Pegasus.
Maximillion Pegasus summoned this spellcaster in an attempt to equip Dark Magician of Chaos but to no avail. Yami tributed Kuriboh and used the Multiply spell to blind Restrict which lead to the downfall of the monster. Basically, the effect of Multiply special summoned a thousand Kuribohs and made Thousand-Eyes Restrict equip the mighty Kuriboh instead of Black Magician of Chaos.
Pai (3x3 Eyes) is the last surviving Sanjiyan Unkara (a tri clops creature who lives a very long time) and carries a third eye in her forehead. As she aged, Pai developed a split personality as a mechanism to cope with her longevity. In fact, she is the only Sanjiyan shown to have more than one personality in the series. One day, Pai’s pet is released and caused the death of Yakumo Fujii. Right before Yakumo’s death, Pai has a last-ditch effort to force her soul in her body. Yakumo appeared with a third eye on the forehead and now, Pai and Yakumo are one and the same in one body. These two characters are intertwined in a conquest to restore their humanity and foil the conquering plans of the Demon-Eye King of the Sanjiyan.
Wisely Kamelot (D-Gray Man) is a member of the Noah Clan who hates the Innocence and Exorcists in the show. The Noah Clan has domain over the Akuma (creatures of dark matter controlled by the Noah) and can single-handedly destroy the human race simply touching them with the Akuma blood virus (fatal to humanity by skin-to-skin contact in which a human’s body starts to break down). Wisely is known to be a weaker Noah than the others but still has the same hatred running through his veins. He is the successor for the Demon-Eye Noah which grants an additional three eyes. He has a total of five eyes and the special powers associated with the extra three eyes are mind-reading, mind manipulation (various techniques over the mind), and mind investigation (telepathy between other Noah members and Noah tracking ability).
Eyes might serve as visual organs but there far more uses for them than that reason. These characters give the term “four eyes” a new meaning for extra eyes exceed the count of four in some circumstances. Also, remember that multiple might seem unneeded; however, there are characters whose existence comes with extra eyes. Honestly, multiple eyes in real life are freaky and that creep factor is in a higher degree in Anime.
Anime empathizes with the creep factor from extra eyes in character design and sets themselves different from others doing the same thing. The eyes we have simply exist to act as a mirror and see the world for what it is even if it is creepy.