Cyclovergence refers to the movement of eyes in opposite directions during the rotation of the head. Synonyms for this phenomenon include cyclodisparity, cyclotorsion, and cyclofusion. Cyclodisparity refers to the difference in visual perception between the two eyes due to a difference in cyclovergence. Cyclotorsion is the rotational movement of the eyes to compensate for the tilting of the head. Cyclofusion refers to the process by which the two separate images received by each eye are merged into a single image by the brain. All these terms are closely related and are used in ophthalmology and optometry to describe the complex mechanisms involved in binocular vision.