The shinigami eyes
From Animepedia
the shinigami eyes are the eyes of a shinigami in the anime death note these eyes can see once looked at thier face can see the name of the person and lifespand.to obtain these eyes you must make a deal with a shinigami the deal goes by this you get the eyes but your lifespan gets cut in half ex.if your going to die in 4hours it shortens to 2hours.