There have been at least five Omen films. The Omen (1976), Damien: Omen II (1978), Omen III: The Final Conflict (1981), Omen IV: The Awakening (1991) (TV) and The Omen (2006), which is a remake of the first movie.
The Aztecs believed the eclipse was an omen. There is no scientific proof than an omen is real. The omen is purely psychological. Studies show that if you believe an omen will bring you bad luck, you will have bad luck because you mentally anticipated it.