diseases of the eye. 45 



Cataract. 



Cataract in the horse is usually the result of previous attacks 

 of disease. It consists of opacity of the crystalline lens, or the 

 capsule of the same. The disease is incurable, because if an opera' 

 tion was performed for the breaking-up or depression of th\ 

 cataract, such as is practiced in human medicine, vision would 

 still be as imperfect as ever without the aid of magnifying glasses, 

 which would be a great inconvenience to the horse, and scarcely 

 of any practical service. 



Woem IN THE Eye. 



Small parasites are occasionally observed in the eyes of horses. 

 They float about in the watery humor, often for a great length of 

 time, without appearing to do any mischief; yet, being a foreign 

 body, they are, to say the least, injurious. The author has never 

 seen but one case of worm in the eye, and that occurred in a 

 horse, the property of a resident of Chicago. The animal was 

 k ept on exhibition for the inspection of the curious, and was the 

 source of considerable profit to the owner. It is possible that 

 such worm might be extracted by a surgical operation. A writei 

 in the "Veterinary Review" thus alludes to this affection : 



" It may also be here noticed that there is a disease which fre- 

 quently affects the eyes of horses in India, but which, as far as I 

 know, has never been observed in Europe. A worm, which, from 

 the description I have received from different people, may be 

 ojmpared to the common ascaris, is generated in the anterior 

 chamber, and can at times be distinguished swimming about, with 

 apparently great vigor, in the aqueous humor. It produces a 

 great deal of irritation and inflammation, the effects of whicl 

 ultimately destroy the organ. The natives of India cure the 

 disease by making an incision through the cornea, and extracting 

 the worm. Though I have never had an opportunity of examin- 

 ing an eye affected with this curious disease, the circumstantial 

 accounts, from several accurate observers, leave no doubt in my 

 mind of its existence ; and the fact accords with what is known 

 to take place regarding the formation of worms, not only in the 

 human body, but more particularly in the liver, lungs, brain, and 

 other orgars jf the inferior animals." 



