AM A UROSIS 547 



attacked the sinuses of the head. The patient is partially 

 or totally blind. The papilla will appear congested. Many 

 cases will recover when the cause is removed. 



ATROPHY OF THE OPTIC NERVE. 



Definition.— It may result from inflammation or be a simple 

 atrophy. Blindness is a prominent symptom. 

 Prognosis.— The prognosis is unfavorable. 



AMBLYOPIA. 



Definition.— Partial blindness. No lesion can be deter- 

 mined. In animals it usually results from poisoning. As a 

 rule when the cause is removed sight is restored. 



AMAUROSIS. 



Definition.— Blindness without visible lesion of the eye. 

 Amaurosis is a symptom and not a disease. The term is 

 falling into disuse as ophthalmoscopy becomes better 

 developed. It may be congenital or acquired. Diseases 

 of the optic nerve, retina, brain and certain poisons are its 

 principal causes. The symptoms are blindness, abnormal 

 dilatation of the pupil which does not react to light. In 

 the early stages the eye appears normal but in time the 

 globe becomes atrophic. Ophthalmoscopic examination may 

 be negative, although usually changes can be noted on the 

 retina or papilla. There is no treatment of value. Cases 

 due to poisons may recover. 



