An optical film which is obtained by dispersing an alkaline earth metal carbonate fine powder into a resin, and which is characterized in that: the alkaline earth metal carbonate fine powder has a mean length within the range of 10-100 nm; the content of the alkaline earth metal carbonate fine powder in the whole optical film is within the range of 0.1-50% by mass; and a surfactant is adherent to the surface of the alkaline earth metal carbonate fine powder. An image display device which is provided with this optical film.
