DISEASES OF THE EYE. 133 



GLAUCOMA. 



Glaucoma is an opacity of the vitreous humor, or of the tunica hya- 

 loidea, characterized by a grayish or sea-green appearance of the eyes 

 which comes on gradually in old age. It terminates in total blindness, 

 and is quite incurable. 



LACERATION OF THE EYELIDS. 



Laceration of the eyelid arises from striking against a rail or other 

 sharp point, a bite from another horse, or other accidental injury. 



Treatment. — The treatment usually consists in bringing together 

 the lacerated parts with two or three separate interrupted stitches (see 

 page 31). Great care is needed to prevent the patient from rubbing his 

 eye against the manger. A linen rag wet with water should be hung 

 loosely from above over the eye; or, if there is some inflammation with: 



Chloride of ammonium, 



Nitrate of potassium aa § iiss. 



Water 1 pint. 



Dissolve the chloride of ammonium and the nitrate of potassium in the water, 

 and as soon as they are absorbed, dip the cloths in the solution and hang them 

 over the inflamed part. 



No part of the injured structure should be cut away, unless it is so hope- 

 lessly lacerated as to make re-union very improbable. There is always a 

 strong natural tendency to re-union of these parts, and therefore, with 

 judicious management, a successful result need not be despaired of, even 

 in very severe injuries. 



DISEASES OF THE LACHRYMAL PASSAGES 



Etiology. — When a weeping or flow of tears over the check is perma- 

 nent, the cause will usually be found in some obstruction of the lachry- 

 mal ducts or canals, which lead from the eyes to the nose, and by 



