Fig. 20. Goniophotograph of a normal open angle representing a view analogous to that shown at higher magnification in Fig. 19. Five alternating dark and light bands are evident in the angle. The uppermost dark band corresponds to Schwalbe's line. The uppermost light band corresponds to the anterior or “nonfiltering” meshwork. The next dark band corresponds to the posterior or “filtering” meshwork. The next light band corresponds to the scleral spur. The final dark band, just above the peripheral iris, corresponds to the ciliary body band. (Photograph courtesy Rodney Gutner, O.D.) (From Freddo T: Ocular anatomy and physiology related to aqueous production and outflow. In: Fingeret M, Lewis T (eds). Primary Care of the Glaucomas. 2nd ed. New York: McGraw-Hill, 2001.)