How Does Vision Influence Balance?

We stand upright because our brain constantly reads two distinct visual "streams": central (foveal) vision and peripheral vision.

One acts like a nail; the other, like a radar. Together, they stabilize posture and calibrate motor skills.

Central Vision: The Precision Anchor

In the fovea (≈ 2°), high-resolution cones detect micro-variations in perspective.

Fixating on a stationary point immediately reduces the oscillation of the center of pressure (–40% in healthy adults; –60% if the vestibules are deficient).

Any drift from this point on the retina signals an imbalance; the sensorimotor loop then triggers a muscular adjustment to "stick" the image back to the center.

During precise shooting or when taking off before a jump, this foveal anchor also serves as a spatial reference for programming the trajectory.

Peripheral Vision: The Speed Reader

Beyond the fovea, rods mainly encode the optical flow. If the lateral scenery moves to the right, the brain concludes that the body is tilting or moving to the left and triggers a counter-correction.

A peripheral pattern rotating at 30°/s causes the trunk to oscillate at the same rhythm, proving that the periphery synchronizes posture with the visual scene.

In running, artificially enlarging this flow (side projectors) prompts the athlete to shorten their strides: they "believe" they are going faster.

Eye-Head Coupling: Keeping the Scene Stable in Motion

To turn the head without seeing blur, the vestibulo-ocular reflex (VOR) counteracts the eye movement within 10 ms.

Insufficient VOR gain (< 0.7) leads to blurred vision, slowed walking, and a widened gait.

Stability of gaze then becomes the essential condition for a safe posture and precise movement.

Hierarchy and Sensory Reweighting

In a stable environment, the system prioritizes the central target; closing the eyes shifts the hierarchy towards the vestibule + proprioception.

In a moving scene (tramway, virtual reality), the periphery dominates; if the flow is inconsistent, the body becomes disorganized despite a clear fovea.

This flexibility explains why older adults, less sensitive in the periphery, oscillate more in a crowded hallway than in front of a fixed wall.

Training Vision for Better Balance… and Movement

Pursuit exercises (8 min, 3 times/week, 4 weeks) reduce the oscillation area by 28% AND decrease lateral dribbling error by 15% in basketball players.

Conversely, blurring vision (stroboscopy, tunnel glasses) is a reliable way to test postural robustness and the ability to maintain a gesture under sensory stress.

In Summary

Central vision fixes the scene, while the periphery estimates speed; together, they feed the sensorimotor loop to maintain balance and guide dynamic motor skills.

Training them solidifies the postural foundation and sharpens gesture performance.

References

1. Rohellec J-L. (2004). Vision and Sport: Performance, Expertise, and High-Level Sport. INSEP.
2. Schubert M. C., & Minor L. B. (2014). Optokinetic Stimulation and Postural Control. In Vestibular Rehabilitation (4th ed.). F.A. Davis.
3. Schubert M. C., & Minor L. B. (2014). VOR Gain Deficits and Functional Mobility. Ibid.
4. Purves D., et al. (2019). Neuroscience (6th ed.). Oxford University Press.