Eye Scope

Deidara has a device over his left eye, functioning as a telescope. As he is a long-range fighter by nature, the device allows him to see his targets from a distance and allows him to find the range between himself and other objects. It is usually hidden underneath his hair.

Trivia

 * Deidara seems to be able to see long distances without this scope as after being revived, he found enemy shinobi lurking near Tobi's hideout; he still needs to close his right eye in order to use his left eye for long distance vision.