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 

 admis^on 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 local 

 measure is a blister, which can usually be applied to advantage 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. 



Ccmses. — 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 (Eeynal), 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 clpudy, wet climate, so constantly associated 



