SUMMARY OF THE ANATOMY OF THE EYEBALL 



66 5 



into about one hundred and eighty membranous processes of extreme 

 delicacy, which do not interfere with its transparency. 



SUMMARY OF THE ANATOMY OF THE GLOBE OF THE EYE 



This summary is intended simply to indicate the relations and the 

 physiological importance of the various parts of the eye, in connection 

 with Fig. 173. 



The eyeball is nearly spherical in its posterior five-sixths, its anterior 

 sixth being formed of the segment of a smaller sphere, which is slightly 

 projecting. It presents the following parts, indicated in the figure : 



SUPERIOR RECTUS 



CHOR010 



OPTJC NERVE 



-INFERIOR RECTUS 



Fig. 173. Diagrammatic section of the eye. 



The sclerotic ; a dense fibrous membrane, chiefly for the protection 

 of the more delicate structures of the globe, and giving attachment to 

 the muscles that move the eyeball. Attached to the sclerotic are the 

 tendons of the recti and the oblique muscles. 



The cornea; a transparent structure, forming the anterior projecting 

 sixth of the globe ; dense and resisting, allowing, however, the passage 

 of light ; covered, on its convex surface, with several layers of trans- 

 parent epithelial cells. 



The choroid coat ; lining the sclerotic and extending only as far for- 

 ward as the cornea ; connected with the sclerotic by loose connective 

 tissue, in which ramify bloodvessels and nerves, and presenting an ex- 

 ternal vascular layer and an internal pigmentary layer (described with 

 retina), which latter gives its characteristic dark-brown color. 



