DISEASES OF THE EYE AND ITS APPENDAGES. 361 



other change in the nutrition of the lens; it may occur as a result of 

 inflammation of the deep structures of the eye. Cataract may be sim- 

 ple, or complicated with ainaurosis, adhesions, etc. 



Symptoms. It is known by the whiteness or loss of transparency of 

 the lens, although the pupil dilates and contracts. Sight may be 

 totally lost; however, evidence is usually manifested that the animal 

 distinguishes light when brought out of a darkened stable. For the 

 most part the formation of cataract takes place slowly, the cases in 

 which it originates very quickly being but few. 



Treatment. There is only one method for the treatment of cataract 

 a surgical operation for the removal of the lens; but this is not advisa- 

 ble, for the sight can not be perfectly restored, and objects would be 

 seen imperfectly without the aid of glasses. 



AMAUROSIS. 



A paralysis of the nerve of sight or the expansion of the retina. 



Causes. This is the result of concussion from a blow upon the fore- 

 head, fracture of bone over the eye, causing downward pressure, rheu- 

 matic inflammation of the optic nerve, or from extension of deep inflam- 

 mation of the eye involving the retina. It sometimes occurs as the 

 result of excessive loss of blood, or of great debility. 



Symptoms. In this disease seldom any observation is made until the 

 animal in its gait and by its action indicates blindness. Generally both 

 eyes are affected. The eyeball remains clear, and the pupil perma- 

 nently dilated. Xo response to light is manifested. 



Treatment. If due to debility, loss of blood, or associated with rheu- 

 matism, general blood tonics may be given in the feed, viz, powdered 

 sulphate of iron, 1 dram ; gentian, 2 drams ; mix vomica, one-half drain ; 

 to be given twice a day. In cases of rheumatism, one-half ounce of 

 saltpeter may be added. 



FILAUIA OCULI WORM IN THE EYE. 



Filaria oculi (proriaiondlly taken <i# the Ittrrn of F. cerrina). This 

 is a small white worm, and is found in the eye, swimming in the aqueous 

 fluid in the anterior chamber. It may be apparently harmless for 

 a long time, but will eventually induce keratitis with inflammatory 

 exudations. 



Trentmcnt. Tin* cornea may bo punctured at its upper and outer 

 margin, and the worm squeezed out with the aqueous humor. The 

 latter will be formed again. 



CORNEAL DEBMATOMA HAIRY TUMOR ON THE EYE11AYL. 



In a few instances this has been seen as a congenital growth. The 

 tumor arises from the cornea or the sclerotic, covered by its respective 

 membrane, with a growth of hair upon its surface. These tumors may 

 be quite prominent or flattened, and are dark in eolor: the hair may 



