DISEASES OF THE EYER 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 tin 
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. 
Worm IN THE EYE. 
Smal] 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 
sven but one case of worm in the eye, and that occurred in a 
horse, the property of a resident of Chicago. The animal was 
kept on exhibition for the inspection of the curious, and was the 
svource of considerable profit to the owner. It is possible that 
such worm might be extracted by a surgical operation. A writer 
in the “ Veterinary Review ” thus alludes to this affection : 
“Tt 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 
eompared 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 which 
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 orga~: of the inferior animals.” 
