Table 1.
Functional classes of human eye movements.
| Class of eye movement | Main function |
|---|---|
| Fixation | Holds the image of a stationary object on the fovea by minimizing ocular drifts |
| Vestibulo-ocular reflexes (VOR) | Holds images of the seen world steady on the retina during brief head rotations (angular VOR) or linear movements (linear VOR) |
| Ocular following responses (OFR) | Short-latency response to motion of the visual scene; represents early motion processing. |
| Optokinetic | Hold images of the visual world steady on the retina during sustained head rotation |
| Smooth pursuit | Holds the image of a small moving target on the fovea – requiring directed visual attention; can be used to negate the angular vestibulo-ocular reflex during combined eye–head smooth tracking |
| Nystagmus quick phases | Reset the eyes during prolonged rotation and direct gaze toward the oncoming visual scene |
| Saccades | Rapidly bring images of objects of interest onto the fovea |
| Vergence | Moves the eyes in opposite directions so that images of a single object are placed or held simultaneously on the fovea of each eye |