}3 



visable to use silver nitrate as it generally leaves a permanent 

 opacity in the cornea. In examing the eye care should be 

 exercised to prevent transmitting the purulent irritating dis- 

 charge Avith its microbes, from the diseased eye to the 

 healthy one. It is also best to separate the diseased animal 

 from all others. If the cornea is perforated, a 1 per cent, 

 solution of eserine or atropine may be used as advised in 

 perforations of the cornea under the head of corneal wounds. 



OPACITIES OF THE COKNEA. 



Scar tissue, infiltrations and organized exudates that su- 

 pervene or result from injuries, inflammation, ulcerations 

 and abcesses are termed opacities. These opacities remain 

 after the intiammation has subsided or after the wound or 

 ulcer has healed, and are not to be confounded with the 

 opacities attending active inflammation. Slightly foggy, 

 weakly clouded, translucent, grayish blue or gray spots, not 

 sharply limited, are mostly found in the outer layer of the 

 cornea and are sometimes called nebulcic. If the opacity is 

 semi-transparent, sharply limited, gray or milk white, it is 

 designated macula. If the opacity is a dense, completely 

 opaque, pearl white, gray or white, regularly distributed or 

 in large spots or stripes, it is called a leucoma. There are 

 also chalk-like, well defined opaque spots which are formed 

 by using acetate of lead or silver nitrate with common salt, 

 calomel or corrosive sublimate; insoluble precipitates are 

 thus deposited in the corneal tissue. Black colored opaci- 

 ties may be spotted or cloudy and are due to bleeding from 

 the vessels in the vascular cornea, or to adhesions of de- 

 tachments of the pigmented iris; the latter may occur as a 

 result of the attachment of the outer surface of the iris 

 with the inner surface of the cornea. 



The harm produced by opacities depend upon their loca- 

 tion; an opaque spot in the center of the cornea cuts off 

 more light than one located near the border. Total blind- 



