CHAPTER X 

 THE ORGANS OF SPECIAL SENSE 



THE ORGANS OF SIGHT 



THE eyes are two globular bodies, situated one in each 

 orbit. They are the organs of vision, and are enclosed 

 partly by the lids and partly by the bony sockets. 



The eyeball is composed of several tunics or coats. In 

 front .we have the conjunctiva, then the sclerotic coat, or 



Upper lid-border. 



Iris with cornea I 



reflex anterior. 



Solera. 



Lower lid-border. 

 FIG. 132. The anterior surface of the eyeball (Pyle). 



white firm structure that surrounds all the ball except 

 the front, where the cornea takes its place. The cornea 

 is a transparent structure that admits the rays of light for 

 vision. Then follow the choroid coat, iris, and ciliary 

 processes, together constituting the second or middle coat 

 of the eyeball. The humors or fluids are the aqueous, 

 crystalline, and vitreous. 



The sclerotic coat is a dense, fibrous layer that in- 

 vests about the posterior five-sixths of the globe of the eye. 



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