TABLE OF CONTENTS 

 Part I— Basic 



Chapter Page 



1. LIGHT AND ITS PERCEPTION 1 



2. A TYPICAL VERTEBRATE EYE: THE HUMAN 6 



A. Structures and their Functions 6 



The Eye a 'Camera', 6 — The Fibrous Tunic, 7 — The Intra- 

 Ocular Fluids, 12— The Uveal Tract, 13— The Pupil, 17 



— The Lens and Zonule, 19. 



B. Optics and Accommodation 22 



Refraction, 22 — Action of a Convex Lens, 2^ — Refractive 

 Errors of the Eye, 26 — Dioptrics of the Normal Eye, 29 — 

 Accommodation, 30. 



C. The Ocular Adnexa 36 



The Oculomotor Muscles, 36— The Lids, 38 — The Lac- 

 rimal System, 41. 



3. THE VERTEBRATE RETINA 42 



A. Histology and Physiology 42 



The Pigment Epithelium, 42 — The Visual-Cell Layer, 45 



— The Bipolar Layer, 46 — The Ganglion Layer, 47 — 

 Miiller Fibers, 48 — Neuroglia, 48 — Horizontal and Ama- 

 crine Cells, 49 — Nutrition of the Retina, 50 — The Optic 

 Nerve, 51. 



B. Types of Visual Cells 52 



General Types — Rods versus Cones, 52 — Single Cones, 53 

 — Rods, 57 — Homology of Rods and Cones, 57 — Green 

 Rods, 58— Double Cones, 58 — Twin Cones, 60 — Ophidian 

 Double Cones, 61 — Double Rods, 62. 



C. The Duplicity Theory 64 



History, 64 — Sensitivity versus Acuity, 65 — Retinal Fac- 

 tors in Acuity, 65 — Retinal Factors in Sensitivity, 68 — 

 Evidence for Duplicity of Vision, 71. 



4. THE VISUAL PROCESS 74 



A. ScoTOPic Vision 74 



Rhodopsin, 74 — Dark Adaptation, 76 — Rod Vision, 79. 



