Black Eye is a Halo 3 campaign achievement. It is earned when the player finds the Black Eye Skull. This Achievement gives 10 Gamerpoints to the player.
It is represented by a blue circle with a skull in the middle. The skull has a black-eyed skull on its forehead.
The Black Eye Skull can be found on "Crow's Nest" on Normal or higher. When you begin the level, look up, and you will see a large pipeline hanging from the ceiling. If you look further down again, you will see a red fencing, which can be jumped on, from there you can already see the skull at the end of the pipeline.