PHYSIOLOGY OF THE EYE OF THE HORSE. 
563 
is, perhaps, some unnatural appearance in the eye, no matter what 
or how it originated : a certificate is then given of unsoundness, 
and there again the matter ends, and the unscientific man can 
do this almost as well as the scientific one. But should the 
horse be brought for the purpose of having a detailed and 
correct opinion of the nature, cause, duration, and probable ter¬ 
mination of the malady, or to be subjected to prompt and deci¬ 
sive treatment, then does the mere man of little study and 
careless practice betray his ignorance ; while the accomplished 
veterinarian unravels every link in the chain of the disease, 
and promptly and effectually administers all the relief of which 
the case will admit. 
The eye is liable to inflammation, common or specific, and 
also to cataract and to amaurosis. 
Common or Simple Ophthalmia .—Though no distinction is 
made either in the nature or tendency of common inflammation 
seated in the same texture in man and the inferior animals, yet 
there are two remarkable points in which it essentially differs in 
the human eye and that of the horse. First, as it attacks the 
human eye, it is considered as a spontaneous or idiopathetic 
affection ; but inflammation in the horse’s eye has, I believe 
I may say without exception, some apparent or assignable 
cause. The animal seems to be exempt from this affection, on 
the same principle that he is less subject to idiopathetic disorders 
in general; not by nature, perhaps, any more than man, but 
from a less irregular mode of living. The seat of common 
ophthalmia is the conjunctiva, and its causes are external: its 
nature is simple, and its symptoms are few and characteristic. 
The treatment also in these cases is in general very simple; 
many cases get well spontaneously after the irritant has been 
removed : others have an inflammation excited which requires 
immediate and active antiphlogistic measures. Should there be 
suspicion of the retention of the foreign body, the most likely 
situation to find it is the concavity of the upper lid ; on elevating 
or everting which, we shall, by means of a probe, probably dis¬ 
cover a hayseed or particle of dirt adhering to or wounding the 
conjunctiva. 
Specific Ophthalmia, the moon-blindness of the farrier’s noso- 
logy, so named by them from a belief that its relapses were 
influenced by the changes of the moon, and from its almost 
certain termination in blindness, is the specific ophthalmia of 
veterinarians. It would appear, from the ordinary account of the 
case, usually to commence its attack at night. The groom dis¬ 
covers in the morning that the horse has got a bad eye, and he 
seldom fails to report that the animal must either have received 
