586 DISEASES AND THEIR TREATMENT. 



Drop on the diseased eye 15 to 10 drops two to three times a day. This rem- 

 edy is a certain cure in most all eye troubles. 



In diseases of the eye due to liver complaint, first give 'a strong cathartic com- 

 bined with 1 to 2 drachms of calomel, and treat the eye as above. 



Amaurosis, or Glass Eye, 



consists in either partial or complete paralysis of the optic nerve, or 

 its terminal expansion, the retina. 



Causes. — Injuries to the brain, causing an extravasation of blood 

 upon the deep Origin of the special nerve of sight (optic), from dis- 

 ease of the internal coat of the eye (retina). It occasionally occurs 

 as a sequel of stomach staggers or indigestion. We have also 

 known it to occur in pregnant mares. Percival mentions several 

 cases of amaurosis occurring in mares with foal, where vision was 

 perfectly restored after parturition. 



Symptoms. — The eye has a peculiar glassy appearance ; the 

 horse carries his head very high,' and is continually moving his ears, 

 and his action is high, lifting his feet as if he were stepping over 

 some obstacle. He is easily alarmed by any noise. The pupil is 

 dilated, and loses its natural elliptical form. If the glare of a lighted 

 candle is brought to bear upon the eye, the pupil refuses to con- 

 tract, thus showing that nervous influence is lost. 



Treatment. — The horse should have rest, and a strong dose of 

 purgative medicine given. If supposed to arise from effusion or 

 pressure on the nerve (optic), blisters and setons to the poll are rec- 

 ommended, and diuretics should be used. In some instances the 

 powdered nux vomica, in doses of one scruple twice a day, has been 

 used with advantage. If amaurosis has continued for a lengthened 

 period, it is incurable, and treatment in such cases would be en- 

 tirely useless. 



Cataract 



is the name applied to a deposition of a pearly white substance 

 within the eye, and is a very common affection in this country. It 

 consists of an effusion of lymph, either on the middle humor (crys- 

 talline lens), or on its capsule, and is variable in size, sometimes not 

 larger than the head of a pin, while in other cases it covers the whole 

 lens. 



Causes.-— Wis generally a result of repeated attacks of specific 

 ophthalmia, or it may even supervene upon a first attack ; " it may 

 follow a severe injury to the eye. 



