III. 



THE BLOODVESSELS OF THE EYE. 

 BY TH. LEBER. 



THE bloodvessels of the globe of the eye form two com- 

 pletely separate systems; the vascular system of the retina, 

 and the choroidal or ciliary vascular system, which are only 

 connected with each other by means of a number of small 

 branches at the point of entrance of the optic nerves. 



The vascular system of the retina, in addition to supplying 

 the retina, supplies also a portion of the trunk of the optic 

 nerve ; whilst the ciliary vascular system, besides supplying 

 the vascular membrane of the eye (including the choroid, 

 ciliary body, and iris), gives branches also to the sclerotic, the 

 margin of the cornea, and the immediately adjoining portion of 

 the scleral conjunctiva. 



The remaining portions of the conjunctiva receive special 

 vessels, which proceed from those of the lids, and form the 

 conjunctival vascular system. 



1. VASCULAR SYSTEM OF THE RETINA. 



The vascular system of the retina is formed by the arteria and 

 vena centralis retinse. The artery is one of the first branches 

 of the ophthalmic artery, and penetrates obliquely into the 

 trunk of the optic nerve, at a distance of fifteen to twenty 

 millimeters from the eye, the vein entering a little nearer to 

 the globe. The latter, as a rule, opens directly into the sinus 

 cavernosus, previously communicating by means of a few large 

 branches with the V. ophthalmica superior, but sometimes 

 opening directly into the latter. More rarely it opens into the 



