ABSTRACT Simultaneous objective (based on binocular eye movement record) and subjective (noniusline displacement) measurements of horizontal and vertical fixation disparity were carried out in order to evaluate the reliability of the nonius‐line method of measuring ocular deviation. Significant differences were found between the subjective and objective measurements. These differences indicate that the nonius‐line method is unreliable for the measurement of ocular deviation or fusional status.
Kertesz et al. (Thu,) studied this question.