506 GLASS EYES. 



greatly prevents any benefit being derived from the opera- 

 tion of couching ; added to which, a horse so operated upon, 

 to have perfect vision, would require to wear spectacles. It 

 has, however, been suggested that, even without glasses, so 

 much benefit might be gained from it as to prevent acci- 

 dents, like running against posts, falling in pits, &c. This, 

 nevertheless, would be greatly overbalanced by the imper- 

 fect vision, which would render the horse so operated on 

 very dangerous from his liability to shy. 



Treatment. — Cataracts of all sizes and shapes are best let 

 alone. Should they cause the horse to shy, blind the eye 

 or eyes in which they may exist. The measures generally 

 pursued, with very doubtful success indeed, are the blowing 

 of mercurial preparations into the eye, the application of 

 caustics, either in powerful solutions, or in substance, to 

 the organ ; and, in short, all kinds of cruelties, more likely 

 to favour the formation, than to cause the dispersion of 

 cataract. 



GLASS EYES, AMAUROSIS, OR GUTTA SERENA. 



This disease, known by the term glass eyes, from the 

 peculiar glassy appearance the organs assume, is generally 

 considered as dependent on a paralytic state of the optic 

 nerves, or of their expansions, the retinae. By others 

 it is, however, thought to arise from the effects of inflam- 

 mation, by which coagulable lymph is placed over the optic 

 nerve, rendering the retina inaccessible to the stimulus of 

 light ; this can hardly be an occasional, and is certainly 

 not the usual cause. The disease, however, is likely to 

 arise from any irritation of the brain ; thus it is found to 

 follow staggers and the loss of large quantities of blood ; 

 which last mentioned cause specially affects the nervous 

 system. The veterinarian should make himself familiar 

 with the appearances of this complaint, otherwise he may 

 lie open to serious imposition. In amaurosis, a horse pre- 

 sents indications of blindness in his manner, though but 

 little in his eyes ; he seems cautious in stepping ; lifts his 

 legs high, and moves his ears quickly, as though endeavour- 

 ing to make up by sound the intelligence lost by the depri- 

 vation of sight : but, above all, a hand moved close to the 

 eye occasions no winking, unless held near enough for the 



