266 



almost altogether wauting, but tliere is always a lack of vigor and en- 

 ergy, bespeaking general disorder. Tlie local symptoms are In the 

 main those of internal oj)hthalmia, with, in many cases, an increased 

 hardness of the eye-ball from effusion into its cavity. The contracted 

 pupil does not expand much in darkness, nor even under the action of 

 belladonna. Opacity advances from the margin, over a part or whole 

 of the cornea, but so long as it is transparent there may be seen the 

 turbid aqueous humor with or without flocculi, the dingy iris robbed 

 of its clear black aspect, the slightly clouded lens and a greenish yellow 

 reflection from the depth of the eye. From the fifth to the seventh d,iy 

 the flocculi precipitates in the lower part of the chamber, exposing more 

 clearly the iris and lens, and absorption commences so that the eye 

 may be cleared up in ten or fifteen days. 



The characteristic of the disease is, however, its recurrence again and 

 again in the same eye until blindness results. The attacks may follow 

 each other at intervals of a month, more or less, but they show no re- 

 lation to any particular phase of the moon as might be inferred from 

 the familiar name, but are determined rather by the weather, the health, 

 the food, or by some periodicity of the system. From five to seven at- 

 tacks usually result in blindness, and then the second eye is liable to 

 be attacked until it also is ruined. 



In the intervals between the attacks some remaining symptoms be- 

 tray the condition, and these become more marked after each succes- 

 sive access of disease. Even after the first attack there is a bluish riusr 

 round the margin of the transparent cornea. The eye seems smaller 

 than the other, at first because it is retracted in its socket, and often 

 after several attacks because of actual shrmkage (atrophy). The upper 

 eyelid, in place of presenting a uniform, continuous arch, has about 

 one-third from its inner angle an abruj)t bend, caused by the contrac- 

 tion of the levator muscle. The front of the iris has exchanged some of 

 its dark, clear brilliancy for a lusterless yellow, and the depth of the eye 

 presents more or less of the greenish yellow shade. The pupd remains 

 a little contracted, except in advanced and aggravated cases, when, 

 with opaque lens, it is widely dilated. If one eye only has suffered, as 

 is common, the contrast in these respects with the sound eye is all the 

 more characteristic. Another feature is the erect, attentive carriage of 

 the ear, to compensate to some extent for the waning vision. 



The attacks vary greatly in severity in different cases, but the recur- 

 rence is characteristic, and all alike lead to cataract and intraocular 

 effusion, with pressure on the retina and abolition of sight. 



The prevention of this disease is the great object to bo aimed at, and 

 this demands the most careful breeding, feeding, housing, and general 

 managemeutas indicated under causes. Much can also be done by migra- 

 tion to a high, dry location, but for this and malarious affections the im- 

 provement of the laud by drainage and good cultivation should be the 

 final aim. 



