"Eye Open" is an orchestral piece on the Via Domus soundtrack. It plays at the end of "A New Day". It serves as the Via Domus character theme for Benjamin Linus.
Having navigated to the 815 front section and retrieved his camera from within, Elliot Maslow is preparing to head back to the beach before being confronted, to his shock, by people not from his plane. Benjamin Linus tells him that they think he's "the one" before he is attacked from behind by Tom Friendly and subsequently sedated by Juliet Burke.
The piece is almost identical to Dharmacide, the main character theme for Ben Linus in the show proper.