CATARACT. 107 



Mr. Hales, of Oswestry, has only seen one case of congenital 



cataract. '* Five years ago," says Mr. H , " a gentleman of 



this neighbourhood wished me to examine the eyes of a foal 

 a few days old, which was foaled blind. I found a perfect cataract 

 in each eye. I stopped the same gentleman's team a weak ago, as 

 it was passing my door. The cataracts were both there, and the 

 horse remains, of course, totally blind." 



Capsular Cataract, that form of the disease, so called, in 

 which the opacity occupies the capsule, exclusively, of the lens, 

 has no relation whatever to the lenticular affection, nor is it any- 

 wise connected with periodic ophthalmia. I believe it, myself, to 

 be the product of common inflammatory action, and that its most 

 frequent origin is injury of some sort, either to the eye itself or to 

 some of its appendages, or even to the parts adjacent. It is the 

 anterior hemisphere of the capsule which becomes opaque, that 

 being thicker and more vascular than the posterior: the latter 

 never, I believe, is found diseased. On this account, the disease 

 is in general not difficult for the close and accurate examiner to 

 distinguish from the lenticular : taking a side-view of the eye, and 

 properly guiding the light to it, we shall, perhaps, be able to detect 

 transparency behind the cataract — to see, as it were, in the rear of 

 it. It appears to have been this kind of cataract, or, if not this, the 

 spurious kind, which has been said and shewn to be absorbable. 



The Origin and Formation of Cataract constitutes one of 

 those branches of science, that, on account of the little that is 

 known for certain concerning the structure and organization of the 

 lens, has given license for a great deal of speculative opinion, into 

 which there will be no occasion for us to enter here. It will be 

 sufficient for us to know that in the horse its common originator 

 is periodic ophthalmia : at the same time, we must not shut our 

 eyes to the fact of cataract having been known in many instances 

 to arise independently of this disease ; and that, in some of these 

 recorded cases, it has all the appearance of being a disease sui 

 generis. And, farther, the case I have mentioned* would seem to 

 shew, that although such a cataract may exist, yet is the eye, the 



* At page 10.>. 



