Motion repulsion is monocular.

Motion repulsion is the illusory enlargement of the angle between objects moving in two different directions of motion. Previous work suggests that motion repulsion occurs under dichoptic conditions, and therefore is binocular. In reference repulsion the direction of motion is misperceived even if only a single direction of motion is presented. In an experiment I show that repulsion under dichoptic conditions is correlated with reference repulsion, but not with binocular motion repulsion. This suggests that motion repulsion proper, which occurs over and beyond reference repulsion, does not occur under dichoptic conditions, implying that motion repulsion is monocular.