4i^ 



roundiDgs of the animal in proper condition and maintaining 

 sufficient light for the animal to see distinctly in all parts of 

 the stall without straining the eyes. As a rule it is best to 

 have the light enter the stall or barn from behind the animal, 

 or from both sides. In man the opaque lens is removed by 

 a surgical operation, and a double convex lens is adj asted in 

 front of the eye thereafter. But this is impracticable among 

 domestic animals, since the double convex lens can not be 

 adjustad to the eye, and the eye would always be hyperme- 

 tropic (farsighted), permitting the animal to see close ob- 

 jects indistinctly and therefore inducing it to shy or become 

 frightened. However the opaque lens is occasionally re- 

 moved in horses and dogs to eliminate the uusightliness of 

 the cataract; but there is always more or less danger of 

 losing the entire eye ball. 



AMAUROSIS. 



Paralysis (palsy) of the retina or optic nerve has been 

 technically named amaurosis. This condition may depend 

 upon tumors in the brain, injury to the optic nerve between 

 the brain and the eye-ball, or inflammation of the retina. 

 Parasitic cysts quite often appear in the brain of sheep and 

 the amaurotic condition of the eye is a characteristic symptom. 



Abscesses sometimes implicate the roots of the optic nerve 

 and amaurosis supervenes. Temporary amaurosis is present 

 during the intoxication period of lead poisoning; poisoning 

 irom Knlmia latijolia ("ivy"); during the comatose condi- 

 tion of the cow in parturient apoplexy (milk fever) ; and in 

 congestion of the brain. Inflammation of the retina is nearly 

 always present in moon blindness and occasionally it termi- 

 in paralysis of the retina — amourosis. Detachment of the 

 retina from the choroid, hemorrhage from the retinal blood 

 vessels, and emboli (plugging by clotted blood) of retinal 

 blood vessels and excessive loss of blood, cause temporary 



