DISEASES OF THE EYE, 291 
Locally the astringent lotions advised for external ophthalmia may 
be resorted to, especially when the superficial inflammation is well 
marked. More important, however, is to instill into the eye, a few 
drops at a time, a solution of 4 grains of atropia in 1 ounce of dis- 
tilled water. This may be effected with the aid of a soft feather, and 
may be repeated at intervals of 10 minutes until the pupil is widely 
dilated. As the horse is to be kept in a dark stall, the consequent 
adimission of light will be harmless, and the dilation of the pupil 
prevents adhesion between the iris and lens, relieves the constant 
tension of the eye in the effort to adapt the pupil to the light, and 
solicits the contraction of the blood vessels of the eye and the lessen- 
ing of congestion, exudation, and intraocular pressure. Should 
atropia not agree with the case, it may be replaced by morphia 
(same strength) or cocaine in 4 per cent solution. Another Igcal 
measure is a blister, which can usually be applied to advantagé on 
the side of the nose or beneath the ear. Spanish flies may be used as 
for external ophthalmia. In very severe cases the parts beneath the 
eye may be shaved and three or four leeches applied. Setons are 
sometimes beneficial, and even puncture of the eyeball, but these 
should be reserved for professional hands. 
The diet throughout should be easily digestible and moderate in 
quantity—bran mash, middlings, grass, steamed hay, etc. 
Even after the active inflammation has subsided the atropia lotion 
should be continued for several weeks to keep the eye in a state of rest, 
in its still weak and irritable condition, and during this period the 
patient should be kept in semidarkness, or taken out only with a dark 
shade over the eye. For the same reason heavy drafts and, rapid 
paces, which would cause congestion of the head, should be carefully 
avoided. ' 
RECURRENT OPHTHALMIA (PERIODIC OPHTHALMIA, OR MOON- 
BLINDNESS). 
This is an inflammatory affection of the interior of the eye, inti- 
mately related to certain soils, climates, and systems, showing a strong 
tendency to recur again and again, and usually ending in blindness 
from cataract or other serious injury. 
Causes.—Its causes may be fundamentally attributed to soil. On 
damp clays and marshy grounds, on the frequently overflowed river 
bottoms and deltas, on the coasts of seas and lakes alternately sub- 
merged and exposed, this disease prevails extensively, and in many 
instances in France (Reynal), Belgium, Alsace (Zundel, Milten- 
berger), Germany, and England it has very largely decreased under 
land drainage and improved methods of culture. Other influences, 
more or less associated with such soil, are potent causative factors. 
Thus damp air and a cloudy, wet climate, so constantly associated 
