Sighting dominance and egocentric localization.

Theories of the perception of visual direction use, either a hypothetical "projection center" midway between the two eyes, or the line of sight of the sighting dominant eye, as a reference point for egocentric localization. Seventy-five observers made judgments of the visual straight ahead. Their judgments varied as a function of both viewing condition and eye dominance. Judgments were biased toward the side of the viewing eye during monocular exposure, while binocular judgments were intermediate in their placement. Both monocular and binocular judgments were shifted in the direction of the sighting dominant eye, suggesting that the reference point for visual localization lies between the midpoint of the interocular axis and the line of sight of the sighting eye.