b CONTEXTS. 



CHAPTER IY. 



REFRACTION IN THE EYE. 



The eye as an optical instrument Laws of refraction, dispersion, etc., bearing 

 upon the physiology of vision Angle alpha Theories of light Theories 

 of colors Color-blindness Refraction by lenses Myopia and hyperme- 

 tropia Spherical aberration Chromatic aberration Formation of images 

 in the eye Area of distinct vision Punctum ca3cum Mechanism of re- 

 fraction in the eye Refraction by the cornea Refraction by the crystal- 

 line lens Simple, schematic eye Astigmatism, . . . Page 70 



CHAPTER V. 



MOVEMENTS OF THE IBIS ACCOMMODATION. 



Direct action of light upon the iris Action of the nervous system on the iris 

 Mechanism of the movements of the iris Accommodation of the eye to 

 vision at different distances Theories of accommodation Changes in the 

 crystalline lens in accommodation Action of the ciliary muscle Changes 

 in the iris in accommodation, 96 



CHAPTER VI. 



BINOCULAR VISION, ETC. 



Erect impressions produced by images inverted upon the retina Single vision 

 with both eyes Corresponding points The horopter Appreciation of dis- 

 tance and the form of objects Mechanism of the stereoscope Binocular 

 fusion of colors Duration of luminous impressions Irradiation Move- 

 ments of the eyeball Muscles of the eyeball Axes of rotation of the 

 globe for the different sets of muscles Action of the recti muscles Action 

 of the oblique muscles Associated action of the different muscles of the 

 eyeball Parts for the protection of the eyeball Eyelids Muscles which 

 open and close the eyelids Conjunctival mucous membrane Lachrymal 

 apparatus Composition of the tears, 115 



CHAPTER VII. 



AUDITORY NERVES TOPOGRAPHICAL ANATOMY OF THE EAR. 



Physiological anatomy of the auditory nerves General properties of the audi- 

 tory nerves Effects of galvanic currents passed through the ear Topo- 

 graphical anatomy of the parts essential to the appreciation of sound The 

 external ear General arrangement of the parts composing the middle ear 

 Anatomy of the tympanum Arrangement of the ossicles of the ear 



