OF THE EYES. 379 



in truth no great expectation can be formed 

 either internally or externally ; more par- 

 ticularly from the former, as the seat of dis- 

 ease is so very remote from the centre of me- 

 dicinal action. If the defect should origi- 

 nate in a contraction of, or compression upon, 

 the optic nerve, very little can be done with 

 an expectation of success ; and much less if 

 it arises from a palsy of that or any neigh- 

 bouring part. 



A cataract, like many other diseases, is 

 attributed by different practitioners to dif- 

 ferent causes, though the greater part coin- 

 cide in opinion that the defect is in the crys- 

 talline humour of the eye, which, becoming 

 opaque, prevents the admission of those rays 

 upon the retina that constitute vision. To 

 enter at large into the professional definition 

 of these distinct diseases, and most minutely 

 into the probable or possible means of relief, 

 would be to extend this subject beyond the 

 limits or couipass of the work itself. I shall 

 therefore reconcile to myself the communi- 

 cation of a fact ahnost universally acknow- 

 ledged — that little, even in the human species, 

 is now expected from the famous operation 



