1. An iris recognition method, comprising the steps of: acquiring an image of at least one eye of a user in an infrared spectrum in an image sensor; processing said image to extract therefrom identification characteristics from the iris as defined by an outer boundary in the eye; acquiring an image of the eye in a visible spectrum in the image sensor substantially simultaneously with acquiring the image of the eye in the infrared spectrum; and prior to processing the infrared image, determining the outer boundary of the iris from the image in the visible spectrum.