VISION. 



779 



developed in hypermetropic eyes, and atrophied or absent in myopic 

 eyes. It is composed of circular fibers, which form a ring parallel 

 with the base of the cornea. The ciliary muscle arises from the 

 sclerotic close to the cornea; its fibers are inserted into the pecti- 

 nate ligament, and extend to be attached to the choroid, as has just 

 been described. 



Ciliary Body. This includes the ciliary processes and the 

 ciliary muscle. 



18 



24 



\26 25 

 27 



Fig. 329. Lateral View of the Orbit, Showing the Nerves. (DEAVEB.) 



1, Antrum. 2, Bristle in the antrum. 3, Loop between orbital and lacrimal 

 nerves. 4, Tarsal plate. 5, Lacrimal gland. 6, Tendon of superior oblique. 7, 

 Pulley of the same. 8, Infundibulum. 9, Frontal sinus. 10, Supra-orbital nerve. 

 11, Supra-trochlear nerve. 12, Levator palpebrse muscle. O, Lacrymal nerve. 

 J, Superior rectus muscle. A, Frontal nerve. 13, Internal rectus muscle. 14, 

 Optic nerve. 15, Short ciliary nerve. 16, Nasal nerve. 17, Ciliary ganglion. 18, 

 Lacrimal nerve. 19, Motor oculi nerve. 20, Patheticus nerve. 21, Abducens 

 nerve. 22, Ophthalmic division of the fifth nerve. 23, Gasserian ganglion. 24. 

 Fifth nerve. 25, Inferior maxillary nerve. 26, Superior maxillary nerve. 27, 

 Orbital nerve. 



Iris. This body is to be considered as a process of the choroid. 

 It is made up of four layers: (1) The anterior epithelium, made of 

 flat cells, which cover the anterior surface of the iris. (2) The 

 stroma of the iris, which consists of connective tissue which contains 

 numerous blood-vessels, which are radially arranged and have no 

 muscular sheaths. In this part of the iris the smooth muscle-cells 

 are collected to form the sphincter and dilator muscles of the pupil. 

 The sphincter muscles are arranged circularly around the edge of 

 the pupil. The dilating muscles run in a radial manner. The 



