ABSTRACT
Saccades are the fastest movements to carry the eye from one fixation direction to another. Saccades were identified on the basis of the modulus of the versional velocity vector. To test whether observed eye velocities during the saccades complied with Listing’s law we investigated to what extent the torsional component of the versional eye velocity was linearly related to the horizontal on the vertical components. A new observation was that for certain idiosyncratic saccade directions unequal torsional velocity appeared. A few studies have recorded the torsional eye position during saccades. It was found that both curved and straight saccades roughly conform to Listing’s law. Although Listing’s law is usually presented as a constraint on the eye’s torsional position in relation to its viewing direction, an equivalent and for saccades more relevant formulation stresses the constraint on the eye’s velocity as implied by Listing’s law.
