DISEASES OF HORSES 349 



upright one become diffuse and indefinite over a given point, it indi- 

 cates opacity on the front of the capsule of the lens. If both upright 

 images remain clear while the inverted one becomes indistinct at a 

 given point, then the opacity is in the substance of the lens itself or 

 in the posterior part of its capsule. 



If in a given case the pupil remains so closely contracted that 

 the deeper parts of the eye can not be seen, the eyelids may be rubbed 

 with extract of belladonna, and in a short time the pupil will be 

 found widely dilated. 



DISEASES OF THE EYELIDS. 



Congenital Disorders. Some faulty conditions of the eyelids 

 are congenital, as division of an eyelid in two, after the manner of 

 hare-lip, abnormally small opening between the lids, often connected 

 with imperfect development of the eye, and closure of the lids by ad- 

 hesion. The first is to be remedied by paring the edges of the division 

 and then bringing them together, as in torn lids. The last two, if 

 remediable at all, require separation by the knife, and subsequent 

 treatment with a cooling astringent eyewash. 



Nervous Disorders. Spasm of eyelids may be owing to consti- 

 tutional susceptibility, or to the presence of local irritants (insects, 

 chemical irritants, sand, etc.) in the eye, to wounds or inflammation 

 of the mucous membrane, or to disease of the brain. When due to 

 local irritation, it may be temporarily overcome by instilling a few 

 drops of a 4 per cent solution of cocaine into the eye, when the true 

 cause may be ascertained and removed. The nervous or constitu- 

 tional disease must be treated according to its nature. 



Drooping Eyelids, or Ptosis. This is usually present in the up- 

 per lid, or is at least little noticed in the lower. It is sometimes but 

 a symptom of paralysis of one-half of the face, in which case the 

 ear, lips, and nostrils on the same side will be found soft, drooping, 

 and inactive, and even the half of the tongue may partake of the 

 palsy. If the same condition exists on both sides, there is difficult 

 snuffling breathing, from the air drawing in the flaps of the nostrils 

 in inspiration, and all food is taken in by the teeth, as the lips are 

 useless. In both there is a free discharge of saliva from the mouth 

 during mastication. This paralysis is a frequent result of injury, by 

 a poke, to the seventh nerve, as it passes over the back of the lower 

 jaw. In some cases the paralysis is confined to the lid, the injury 

 having been sustained by the muscles which raise it, or by the supra- 

 orbital nerve which emerges from the bone just above the eye. Such 

 injury to the nerve may have resulted from fracture of the orbital 

 process of the frontal bone above the eyeball. 



The condition may, however, be due to spasm of the sphincter 

 muscle, which closes the lids, or to inflammation of the upper lid, 

 usually a result of blows on the orbit In the latter case it may run 

 a slow course with chronic thickening of the lid. 



The paralysis due to the poke may be often remedied, first, by 

 the removal of any remaining inflammation by a wet sponge worn 

 beneath the ear and kept in place by a bandage ; second, when all 

 inflammation has passed, by a blister on the same region, or by rub- 



