Tolerance and Nature of Residual Refraction in Symmetric Power Space as Principal Lens Powers and Meridians Change

Figure 5

Optical crosses for a prescription lens with principal powers along 10° and along 100° and a compensation lens along a meridian at 20° and along 110°. In Figure 3(b), these latter data have a power matrix compensation represented at points like where both eigenvectors and eigenvalues differ from those of the prescription power matrix represented at .