112 On the Restoration of Vision. 



have been made for its alleviation. The conical form of the 

 cornea has been attributed to an over-distention of that tunic, 

 occasioned bv a superabuiidant secretion of the aqueous humour, 

 which continuallv stretching the cornea, has gradually occasioned 

 it to yield to the pressure from within, and thus produced the 

 alteration in its form. To remove this supposed over- distention, 

 it has I)een usually recommended to evacuate the aqueous hu- 

 mour, by puncturing the cornea, and afterwards to employ 

 pressure, astringent collyria, &c. to prevent its reaccutnulation. 

 Experience has, however, sliown the total inutility of these 

 modes of practice. The operation of evacuating the aqueous hu- 

 mour has been, in some instances, repeated several times, with- 

 out any permanent advantage being found to result from it ; and 

 although it is an operation neither painful nor difficult to per- 

 form, yet it is sometimes dangerous; for if the crystalline lens 

 should be wounded bv the instrument with which the puncture 

 is made, cataract will most likely ensue ; and I have been in- 

 formed of a case, where this actually occurred, during the at- 

 tempt to evacuate the aqueous humour. 



Having, at an early period of my practice, been impressed 

 vvith the opinion, that the conical form assumed bv the cornea 

 in this disease, was the effect of a morbid growth of that tunic; 

 and tiiat the short-sight experienced by the patient, was to be 

 attributed to its increased refractive power, which, together with 

 that of the crystalline lens, brought the rays of light to a point 

 far short of the retina, it occurred to me, that as it was impossi- 

 ble to remove the morbid growth of the cornea, without ren- 

 dering it unfit for the transmission of light, a useful degree of 

 vision might be restored by the removal of the crystalline lens. I 

 was the more strongly led to form this conclusion, after having 

 myself tried the experiment of looking through deep convex 

 spectacles, such as are em])loyed by patients after the removal 

 of cataract, which, I found, produced a confusion of sight, very 

 similar to that which I had heard described by persons in whom 

 the cornea had been conical in the extreme degree. I therefore 

 resolved, mere than six years since, while surgeon to the West 

 of England Eye Infirmary, instituted at Exeter, to remove the 

 crystalline lens in a case in which that body had become opake, 

 and also affected with conical cornea. Some circumstances, 

 however, prevented the j)atient, who was a young woman, and 

 a pauper, from being sent to me to the Infirmary. About three 

 years since, another patient, from the country, an old woman,, 

 nearly seventy years of age, placed herself under my care, la- 

 bouring under this disease, accompanied vvith cataracts, in whom 

 I successfully removed both the cataracts, and had the gratifi- 

 cation to find her vision thereby restored to an extent which far 



surpassed 



