The Oculist's Eye: Connections between Cataract Couching, Anatomy, and Visual Theory in the Renaissance.

We now know that cataract couching involves depressing an occluded crystalline lens to the bottom of the vitreous chamber, but from the time of Galen until the seventeenth-century cataracts were thought to be separate concretions arising between the crystalline lens and the pupil. From Antiquity through the Renaissance, the combination of visual theory in which the crystalline humor is the author of vision, and surgical experience­that couching cataracts restored some degree of sight­resulted in anatomists depicting a large space between the crystalline lens and the pupil. In the Renaissance, oculists­surgical specialists with little higher education or connections to learned surgery or medicine­overwhelmingly performed eye surgeries. This article examines how the experience and knowledge of oculists, of barber-surgeons, and of learned surgeons influenced one another on questions of anatomy, visual theory, and surgical experience. By analyzing the writings of the oculist George Bartisch (c. 1535­1607), the barber-surgeon Ambroise Paré (1510­1590), and the learned surgeon Hieronymus Fabricius ab Aquapendente (1533­1619), we see that the oculists' understanding of the eye­an eye constructed out of the probing, tactile experience of eye surgery­slowly lost currency among the learned toward the beginning of the seventeenth century.