Vergencia

Vergencia, in vision science, refers to the set of eye movements that align the lines of sight of both eyes toward or away from an object so that the image falls on corresponding retinal points. These movements are disconjugate, meaning the eyes rotate in opposite directions, and are coordinated with accommodation to maintain single binocular vision as the gaze shifts from far to near.

The two main vergence movements are convergence and divergence. Convergence occurs when the eyes turn inward to view a near object; divergence when they turn outward to view a distant object. Vergence is typically measured in diopters of vergence or prism diopters and is driven by the spatial demand of the object distance, often linked with the near reflex which also involves accommodation and pupil size.

Clinical relevance is high in ophthalmology and optometry. Abnormal vergence can cause symptoms such as eye strain, headaches, or diplopia. Common conditions include convergence insufficiency, where near convergence is weak, and various divergence or accommodative-vergence disorders. Assessment uses tests such as the cover test, prism vergence ranges, and near/far point measurements. Treatments may involve vision therapy or prism glasses, and surgical options for certain persistent strabismus cases.

Outside vision science, the term vergencia is less common in modern usage; in general Spanish, it can denote inclination or tendency, but in scientific contexts it primarily refers to the vergence movements of the eyes.

See also: vergence, convergence, divergence, diplopia, strabismus, accommodation.