348 DISEASES OF CATTLE. 



and extends over the cornea, thus interfering with vision. It may 

 <;row from the onter angle, or even from either the superior or in- 

 ferior hemisiohere of the eyeball. The figure is invariably that of a 

 triangle, with its base on the white of the eye and its apex more or 

 less advanced over the cornea toward its center. 



The distinguishing characteristics are the constancy of the tri- 

 angular form, and the facility with which the whole of it may be 

 taken hold of with a pair of foi'ceps and raised into a fold on the 

 cornea. Every other kind of excrescence attached to this membrane 

 continues firmly adherent to it, and can not be folded and raised from 

 the surface of the cornea in any manner whatever. 



Treatment. — Eaise the fold and dissect it away from all points of 

 attachment. 



TRICHIASIS (INVERSION OF THE EYELASHES). 



In the simplest form the eyelashes bend inwardly, touching the 

 eyeball, causing irritation and simple conjunctivitis. It may be also 

 associated with- entropion. 



Treatment. — The offending ej'elashes should be cut off or pulled 

 out. In case the natural growth of the eyelashes is directed inward, 

 an operation similar to that for entropion becomes necessary. 



ENTROPION (INVERSION OF THE EYELID). 



In inversion of the eyelid the eyelashes soon irritate the anterior 

 face of the cornea and produce more or less inflammation and opacity. 

 The inversion may be due to the growth of a tumor within or with- 

 out the lid, to abscess, laceration, or injury, causing the lid to lose its 

 natural conformity to the ej'eball, ulcerations, etc. Surgical inter- 

 ference in either case becomes necessary to restore the lid to its 

 natural direction. 



ECTROPION (EVERSION OF THE EYELID). 



This serves to injure the eye by permitting dust or other foreign 

 substances to enter the eye and interferes with the natural removal 

 of them. 



Treatnwnt. — A delicate surgical operation — the removal of an 

 elliptic section of the palpsebral conjunctiva — may remedy the defect. 



TUMORS OF THE EYELIDS. 



Occasionally tumors form upon or within the substance of the eye- 

 lid. They may be of a fibroid nature and arise from the follicles 

 of the hair as sebaceous tumors or may be in the form of an abscess. 

 In debilitating diseases the lids sometimes become swollen and puffy, 

 a condition which may possibly be taken for the growth of a tumor. 

 This generally disappears with the improvement of the health of the 



