Fig. 2. Anterior chamber angle width. A Shallow anterior chamber with a more anteriorly located lens than is shown in Figure 1. Apposition of the lens and iris in the pupillary zone is increased, producing a relative pupillary block that interferes with aqueous flow from the posterior to the anterior chamber. The pressure differential between the posterior and anterior chambers is increased. (Kolker AE, Hetherington J Jr: Becker and Shaffer's Diagnosis and Therapy of the Glaucomas, P 42. St. Louis, CV Mosby, 1970)