Figure 2. Optical characteristics of the -10 dioptre cylindrical lenses.
(a) Circular square wave test grating (1 cycle/°) viewed normally (no lens). (b) The same grating viewed through the -10 dioptre cylindrical lens, with the lens axis aligned horizontally, attenuating horizontal and preserving vertical contours. (c) The radially symmetric distribution of power over spatial frequency for the test grating viewed normally. (d) The radially asymmetric distribution of power over spatial frequency for the same grating when viewed through the -10 dioptre cylindrical lens with the lens axis aligned horizontally. Contours orthogonal to the axis are preserved while contours parallel to the axis are attenuated. Power spectra shown in (c) and (d) are normalized to the peak power (black).