What Role Does Vergence Play in Stability?

Vergence refers to the disjunctive movements of the eyes: convergence for a near target, divergence for a distant target. Much more than a simple optical adjustment, this mechanism enriches visual feedback, stimulates ocular-motor proprioception, and real-time alters postural organization.

A "Zoom" that Recalculates Posture

As the target moves closer, the angle of convergence increases; this modifies the cortical spatial map and subtly shifts the internal representation of the body. Romberg test: target at 40 cm → sway decreases vs target at 3 m (Lê & Kapoula 2008).

Eye-Foot Coupling

The ocular-motor fusional signals activated in convergence connect to the cerebellum with plantar signals; variability of the center of pressure decreases by ~20% (Mathieu 2025).

A simple "stereogram" simultaneously recruits vision + touch to stabilize the body.

Boosting Anticipatory Adjustments

Convergence excites the vestibular nuclei via the reticulo-ocular pathways: tone increases before action. CMJ protocol: convergence before jump → stabilization post-reception –22%, peak force slightly increases.

Rapid Plasticity and Motor Transfer

8 sessions (8 min × 3/week) → gains maintained for 2 weeks; among basketball players, –15% lateral error in dribbling (Matsuura 2024, Mathieu 2025).

Limitations and Indications

Less effect if there is an accommodative deficit or visual fatigue; brief training is recommended. Applications: post-sprain rehabilitation, warm-up for explosive athletes, prevention of convergence dizziness (Morize & Kapoula 2017).

In Summary

Vergence resynchronizes the sensorimotor loop, accelerates anticipatory adjustments, and enhances both static and dynamic stability. Just a few minutes are enough to prepare for more powerful and precise movements.

References

1. Lê H. & Kapoula Z. (2008). Effects of fixation distance on postural sway.
2. Mathieu L. (2025). The Impact of Ocular Vergence (IFMK thesis).
3. Matsuura T