To the Editor.
—I read with great interest Dr. Schweitzer's communication in the April 1967 issue of the Archives (77:548), dealing with the polygonal pattern of the cornea. I have been photographing the same pattern for over a year (Pentax Spotmatic camera loaded with Agfa Isopan Record Film). With appropriate excitor and barrier filters before the flash and camera, the fluorescent pattern is readily recorded.There are a number of ways of inducing or observing the pattern. For instance, if a glass slide is pressed against the cornea in the presence of fluorescein, a mosaic of dark lines against a fluorescent background may be seen. On removing the glass slide and allowing the subject to blink, the lines take up fluorescein and the polygons become fluorescein-free. The pattern then is identical to that induced by simple massage of the cornea through the lid.In the absence of fluorescein, the