dissociated vertical deviation
A condition where, upon occlusion or dissociation of one eye, the occluded eye deviates upward, while the viewing eye maintains fixation. When the right eye fixates, the left eye deviates upward (left hyperdeviation). Conversely, when the left eye fixates, the right eye deviates upward (right hyperdeviation). This vertical misalignment of the occluded eye is only present during monocular viewing conditions.