SUMMARY OF THE ANATOMY OF THE EYE. 



67 



their dimensions, etc., the reader is referred to the descrip- 

 tions just given of these parts. In this summary, we propose 

 simply to show the relations of the various parts, giving, at 

 the same time, a brief statement of their physiological im- 

 portance. This end will be attained by a full explanation of 

 Fig. 5, which represents a section of the human eye, and 

 shows the relations of its various coats, humors, etc. 



FIG. 5. 



-R. 



CKo. 



Cor. 



R. 



Section of the human eye, taken from Helmholtz, and slightly modified. (Revue des cours 

 scienti/iques, Paris, 1868-1869, tome vi., p. 215.) 



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. The posterior five-sixths 

 presents the following coats, indicated in the figure : 



