Accommodation in Binocular Contour Rivalry

Although contour rivalry is known to suppress the contribution of the non-dominant eye to some visuomotor mechanisms such as the pupillary light reflex, there have been no reports of the impact of rivalry on accommodation control. In the situation where the accommodation demands in the two eyes are in dynamic conflict, it has been reported that the accommodation response can be modelled in terms of a vector average of the appropriate response in the two eyes. This study compared the binocular interactions in the accommodation system with rivalrous and non-rivalrous stimuli. Accommodation was continuously monitored with an infrared optometer, while the accommodation demand in the two eyes was dynamically modulated independently in the two eyes. When the visual target was perceptually rivalrous the previously described binocular interactions were abolished and the accommodation response closely followed the accommodation demand presented to the dominant eye.