If you are following an object, the saccades routine itself is put on hold and you get more or less continuous eye motion, complete with smooth focus and field-of-view adjustments. I'm doing this for fun when walking alongside slow-rolling cars - the end result occasionally "looks like" a tracking shot straight out of a movie.

Edit: ...OK, field-of-view doesn't vary that much, unless you are Colonel Steve Austin with the telephoto augmentation.