PPT Slide
Notes:
If the light rays passing through the two pinholes in Scheiner’s Disk come from different sources, then one source can remain fixed while the other is can be repositioned. By adjusting the moveable source horizontally and vertically, the isolated ray of
Having made this adjustment, the displacement distances _x and _y are measures of the ray aberration of the eye at the given pupil point. A modern, computerized version of this basic idea which samples the pupil at many locations sequentially was describ