118 SURGERY. 



move the cataract from the axis of the vision, and is performed by 

 a couching needle passed through the outer side of the sclerotica, 

 about two lines from the margin of the cornea. 



Producing Absorption. — The needle is introduced in the same 

 manner as in depression, the lens broken up and subjected to the 

 absorbing influence of the aqueous humour. 



AMAUROSIS. 



Is an imperfection of vision, arising from some change in the 

 retina, optic nerve, brain, or fifth pair of nerves. 



Sy^nptoms. — The sight is impaired by degrees ; at times vision is 

 more impaired than at others ; objects appear double, crooked, or 

 discoloured ; black spots or flashes of light, a vacant stare, dilated 

 pupil, and but little motion of the eyelids, indicate amaurosis. There 

 is often a want of the natural colour of the pupil, which may cause 

 it to be mistaken for cataract, from which it is most certain to be 

 distinguished by the catoptric test, as well as by rational signs. The 

 usual causes are circumstances which over-stimulate the retina, such 

 as glaring lights, heats, intemperance, tight neck-cloths ; also in- 

 flammation, concussion, extravasations, tumours, &;c. 



Treatment. — Should it be inflammatory, produced by wounds, 

 lightning, or exposure to intense light ; or if there are plethora, head- 

 ache, giddiness, turgid countenance, and frequent flashes of light 

 when stooping ; or if the complaint has followed a suppression of 

 any accustomed evacuation, or the drying up of an habitual ulcer or 

 eruption, then the antiphlogistic treatment must be adopted, — bleed- 

 ing, cupping, counter-irritants, and purgatives. Should it be atonic, 

 the result of a protracted illness, great loss of blood, over-lactation, 

 leucorrhcea, or other debilitating circumstances, it is attended with 

 pallid lips, dilated pupils, trembling pulse, and despondency of mind. 

 The patient usually sees best after eating, and in a strong light. The 

 discharge or other source of exhaustion should be corrected, and 

 the system strengthened by fresh air, tonics, quinine, steel, good 

 living, &c. The secretions should be well regulated, and the 

 cutaneous and general circulation be promoted by exercise and 

 bathing. 



Should it be sympathetic, supervening on jaundice, some disorder 

 of the stomach, or worms, the general health must be regulated 

 before a cure can be expected. It may arise from tumours near the 

 eye and carious teeth, which should be removed. If it follow an 

 injury of the fifth pair of nerves, the wound should be dilated ; or if 

 it be healed, the cicatrice must be cut out. Should it follow the use 

 of tobacco or opium, it may be relieved by a cold shower-bath, 

 counter-irritation, and electricity. Should it be organic, the treat- 

 ment should be palliative. 



