Definition of "cyclorotation"

In measuring eye position, for instance, both Fick and Wundt had adopted procedures which did not treat the co-ordinate frame of the primary position as fundamental. Rather, they related cyclorotations to the visual plane—which is variable—instead of to the horizontal in the primary position.

1993, Timothy Lenoir, Hermann Von Helmholtz and the Foundations of Nineteenth-Century Science, University of California Press, page 151

The images of horizontal lines in the upper visual field acquire a gradient of cyclorotation with one sign, and those in the lower visual field acquire a gradient of cyclorotation with the opposite sign, as shown in Figure 7.8b.

1995, Ian P. Howard, Brian J. Rogers, Binocular Vision and Stereopsis, Oxford University Press, page 269

Also shown are the coefficients of the residual wavefronts assuming a partial correction of the original wavefront due to a cyclorotation of the eye. To estimate how much error may induce due to the cyclorotation of the eye, the residual RMS wavefront error as well as the residual high-order RMS wavefront error for each of the rotation angles is shown.

2008, Guang-ming Dai, Wavefront Optics for Vision Correction, Society of Photo-Optical Instrumentation Engineers, page 192