1. A method implemented by a data processor for locating pupils of a subject comprising the steps of: 1) obtaining at least a partial image of a face of a subject containing an image of at least one pupil, 2) cropping a first pixel array having a high probability of containing an iris and pupil of said subject from said image, said pixel array being slightly larger than a naturally occurring iris, 3) verifying that said first pixel array contains an image of said pupil.