56 THE EXTERIOR OF THE HORSE. 



Diseases. — The diseases of the eye are numerous and more or 

 less grave. They are : 



Nuage is constituted by a slight oi^alescence of the cornea. 



Albugo is a complete o^jacity of a variable area. 



Leucoma is a cicatrix of the cornea. 



Glaucoma is a greenish coloration of the vitreous humor. It is grave. 



Cataract is indicated by a partial or total opacity of the crystalline lens. It 

 is a serious affection. 



Amaurosis or goutte sereine is due to a paralysis of the retina. It may exist 

 only on one or on both sides. 



Hiidrojmi is an augmentation of the volume of the globe of the eye due to a 

 hypersecretion of the aqueous humor. 



Simple ophthalmia is an inflammation of the conjunctiva. 



Periodic fluxion is a periodic inflammation of the whole eye, which termi- 

 nates in the total abolition of sight by the formation of a cataract after a variable 

 period. 



Lippitude is an inflammation of the Meibomian glands and the free border 

 of the eyelids. The eye often becomes covered with the secretion of these 

 glands. It is called blear-eye. 



Trichiasis consists of an inversion of the superior eyelashes against the ocu- 

 lar globe. 



Encanthis is a hypertrophy of the caruncula lachrymalis. 



Melanotic deposits may form on the preceding structure ; warts may grow on 

 the eyelids. 



Onglet is nothing else than an inflammation of the nictitans membrane.* 



Blemishes. — The blemishes of the region of the eyes are denu- 

 dations, (ibrasions, and wounds of the superciliary arches. They are the 

 consequences of injuries received by striking tlie head against resisting 

 objects, etc., or of diseases, as epilepsy, when the animal falls to the 

 ground or when he strikes his head against a wall during an attack 

 of vertigo. Sometimes they are complicated by fractures of the orbital 

 arches. 



Under other circumstances, the eyelids become the seat of abra- 

 sions, lacerations, or deformities of their free border, — e.g., ectropion and 

 entropion. The deformity which follows periodic fluxion should be 

 taken into serious consideration. It has been observed that the supe- 

 rior eyelid of the eye, after several attacks of this disease, becomes 

 angular, from ocular atrophy, towards the nasal angle, which gives to 

 the palpebral opening a triangular form instead of that of a regular 

 oval. 



Finally, all abnormal colors of the cornea or the media of the eye 

 constitute blemishes to which we must give the most serious prognosis. 



1 1 have often, in practice, met with eyes affected with strabismus, — external, internal, and 

 oblique. This was easily remedied by the simple section of the antagonistic muscle. (Harger.) 



