1 14 On the Restoration of Vision. 



ten or twelve inches from the eve, nearty a'' well as she ever re- 

 collects to have done. The usual cataract spectacles for nenr 

 objects, of two inches and a half focus, confused her sight nearly 

 in tlie same manner as before the crystalline lens was removed, 

 while with those of nine or ten inch foci, her capabiHty of seeing 

 minute objects was somewhat improved. She saw objects at a 

 distance better without than with any glass I could find ; whereas 

 the usual standard for distant vision, after the operation for ca- 

 taract, is four inches focus. She now neitlier uses a glass for 

 near nor distant objects, has again returned to service ; and a 

 gentleman told me, who has recently seen her, that she accu- 

 rately described to him an object which was considerably more 

 than a quarter of a mile distant. Twelve months after under- 

 going this operation, I operated upon the other eye ; but she 

 again left town before the eye had recovered itself, and before 

 the lens was entirely absorbed. Previously, however, to her de- 

 parture, she could read small print with this eye, by the assist- 

 ance of a convex glass of two and three quarters inches focus, 

 while with one of nine inches focus the sight was greatly ini- 

 prmed in viewing distant objects. 



As the degree of conical form of the cornea appeared to be 

 the same in both eyes, and as the patient was ecjually blind in 

 both eves before the operations, it is a curious circumstance, and 

 deserving notice, that the two eyes should require glasses dif- 

 fering so much in their refractive power. Not being able to 

 obtain any other information from the patient as to the pro- 

 gressive amendment of her vision, during the twelve months she 

 remained in the country, between February 1815 and February 

 18 IG, when she underwent the operation upon the second eye, 

 except " that her sight continued to get stronger," (an indefinite 

 mode of expression made use of by poor jieople in their recovcrv 

 from almost every species of diseased eve,) 1 carmot undertake 

 to afford any authentic data for the hvjJothesis which I venture 

 to offer as an explanation of this pha;non)enon. 



It appears to me that the greater degree of improvement of 

 vision in the eye first operated upon, might be occasioned by 

 the increased susceptibility of the retina from the exercise of that 

 organ, and the power the eye had acquired of adapting itself to 

 see near and dis'tant objects distinctly, during the interval of 

 twelve mon-ths the patient was absent ; whereas the trial with 

 the two and three quarters convex glass for near objects, and 

 nine for distant ones, on the eve last operated upon, was made 

 01: !y a few weeks after the operation, and even before the atten- 

 dairt inflammatory action had subsided, or the whole of the lens 

 become absorbed. I am led to adopt these opinions from ob- 

 servations made in numerous instauces upon persons who have 



successfijlly 



