A characteristic pattern of dissociated eye movements was observed in a large proportion of our patients with a variety of craniosynostosis syndromes. These anomalies simulate overaction of the inferior oblique and underaction of the superior oblique muscles which, however, cannot fully explain the abnormalities. In a number of cases, excyclorotation of the muscle cone was observed, with the upper pole of the eye tilted away from the midline. It is postulated that such excyclorotation of the eyes will lead to dissociated eye movements which can be explained on physiological grounds according to Hering's law. This paper presents a review of our patients and evidence to support this hypothesis.