Fig. 1. Anterior chamber angle width. Cross-sectional diagram of a deep anterior chamber with a nearly flat iris plane, minimal apposition between the iris and lens at the pupil, and a wide-open angle entrance to the filtration area. In this type of eye, aqueous passes easily from the posterior chamber through the pupil into the anterior chamber and out through the filtration area. (Kolker AE, Hetherington J Jr: Becker and Shaffer's Diagnosis and Therapy of the Glaucomas, p 42. St. Louis, CT Mosby, 1970)