Annihilator (1986)?
http://www.imdb.com/title/tt0090649/Told the tale of a newspaper reporter who has to miss a vacation (having won a "contest") with his girlfriend Angela, a scenario which, in the style it was filmed starts off very prosaic and normal until, as he narrates the entire film as a flashback, he finds her return plane had "gone off the radar" for 90 minutes, and returns, but delayed. He gets unnerved watching Angela speaking to a mysterious man in sunglasses,who seems to be watching the passengers leave the plane, asks who it was- and she denies having spoken to anyone. She is also unaware the plane was "delayed and missing". She begins acting strangely and having odd meetings with unknown people, and as the reporter begins to investigate things and ask more questions, she tries to kill him and he finds she's now a terminator-like robot(complete with the same kind of eye-tracking visuals from that film).
