How does optokinetic nystagmus keep an image stable on the retina?

Optokinetic nystagmus (OKN) is a reflex mechanism that stabilizes visual input by ensuring the eyes move in the same direction and at approximately the same speed as a moving scene. This process relies on the optokinetic reflex (OKR), a feedback loop where velocity-sensitive ganglion cells in the retina detect image motion and send signals via the brainstem to the eye muscles.123

The resulting movement is a "sawtooth" pattern consisting of two phases:34

• Slow Pursuit: The eyes move smoothly to track a specific part of the visual scene, effectively keeping that image stationary on the retina.24
• Quick Reset: Once the eyes reach their limit of movement, they perform a fast, saccade-like jump in the opposite direction to fixate on a new part of the scene, allowing the cycle to repeat.34

While OKR specifically compensates for slower image motion, it works in conjunction with the vestibulo-ocular reflex (VOR), which handles faster movements caused by head rotation, to maintain a stable gaze.13