40 



skilled surgeon and are, many times, done after the lens has 

 become opaque or the operation is followed by opacity of the 

 lens, destroying the vision. The writer observed a case of 

 occlusion of the pupil in both eyes of a three year old horse 

 that was brought to the free clinic at the experiment station 

 in Auburn. The cornea and aqueous humor were transpa- 

 parent, and the occlusion was very probably a result of acute 

 iritis. A strong solution of atropine was dropped into the 

 eye but the iris was so firmly fixed it couid not be detached. 



Excessively developed or large "soot balls" "grape-like 

 bodies," hanging from the inner aspect of the superior part 

 of the free margin of the iris, interfere with, or obstruct, the 

 passage of light into the eye. The large, brown, flake -like 

 bodies are quite frequently the cause of shying and cases 

 have been recorded where complete blindness appeared as a 

 result of these "soot balls" entirely closing the pupil. By 

 a surgical operation they could be removed ; this should be 

 attempted only by a skillful operator. 



Some white horses possess such a high degree of sensi- 

 tiveness of the eye to light that in clear sunshine the pupil 

 is closed by complete conntraction and the animal cannot see 

 until the sun sets. 



CATAEACT. 



All opacities of the crystalline lens, regardless of size, 

 origin or condition, are embraced by the general name cata- 

 ract. A false or spurious cataract is produced by collections 

 of pigment on the capsule of the lens, resulting from the 

 tearing loose of the attachment of the iris to the capsule. It 

 appears in dark, almost black, colored spots on the anterior 

 surface of the capsule. True cataract means that there must 

 be opacity in the substance of the lens or its capsule. If 

 the opacity is in the substance of the capsule it is known as 

 capsular cataract, and when in the substance of the lens, it 



