222 Diseases of the Eyes and Ears, 



involved in the inflammation in common with other 

 tissues of the organ. 



Symptoms. — The colour of the iris is changed to a 

 reddish brown, by the presence of blood and the 

 bringing into view bloods-vessels not discernible in the 

 healthy state, and the colour spreads also beyond the 

 circle of the cornea. The patient cannot bear the light, 

 and to shut it out the pupil contracts, and is more or 

 less immovable by reason of the inflamed condition of 

 the structures. The unopposed progress of the disease 

 leads to extravasation of blood, deposit of opaque lymph, 

 possibly the formation of pus, and total destruction of 

 the organ as far as vision is concerned. 



Treatment. — Local bloodletting by lancet or leeches ; 

 hot fomentations ; secure free action of the bowels, the 

 patient being kept in a dark, but airy room. Considerable 

 fever is usually present, which must be met by febrifuges ; 

 and when it has subsided daily doses of iodide of 

 potassium with extract of gentian may be given to 

 remove the deposit of inflammation. A seton behind 

 the head is often beneficial. 



Amaurosis, or Gutta Serena^ also known as Glass 

 Eye, is a serious impairment of vision, due to disordered, 

 if not structural, changes in the condition of the optic 

 nerve, retina, or brain, the result of violent shocks, as 

 falls, blows, &c. The first effect is probably paralysis, 

 or inflammation accompanied with extravasation of blood, 

 lymph deposits, or formation of tumour, with ultimate 

 suspension or total loss of nerve power. The disease 

 may be associated with extreme debility, the result of 

 anaemia, haemorrhage, inordinate lactation, or other 

 causes. 



Symptoms. — Defective vision, in some instances de- 

 veloping slowly, and in others very suddenly. In the 

 first instance the animal fails to see objects until he is 

 close upon them, and in the latter he approaches with 

 great caution and uncertainty, usually relying on his 

 acute sense of smell as he moves about alone. Ulti- 

 mately the power of vision is entirely absent. Any signs 

 of unusual heat, pain, or redness of the eyes, or cloudi- 



