LOCAL DISEASES OE THE EVE 509 



LOCAL DISEASES OF THE EYE. 



(1) Traumatisms. 



Burns and scalds. The cornea may be injured and slough. 

 Enucleation may be necessary. If by lime and acids there 

 is often symblepharon. To treat such cases insert a neutral 

 oil, as castor or olive oil. 



Foreign bodies such as pieces of steel. Apply 2 per cent, 

 cocaine and remove the particle. If allowed to remain in 

 the eye it may become encased in fibrous tissue and followed 

 by vitreous degeneration and opacity, gross pigmentation of 

 the choroid, iritis and optic atrophy. 



Flies may carry micro-organisms and cause conjunctivitis. 



Abrasions of the cornea from inverted eyelashes or scratches 

 from baby's finger nails, &c. 



Contusions and concussion injuries (black-eye). Such may be 

 followed by mydriasis, rupture of the ball, dislocation of the 

 lens, haemorrhage into the anterior chamber, vitreous or 

 retina, rupture of the retina or choroid, opacity of the lens, 

 pigmentary changes in the retina, some optic atrophy, detach- 

 ment of the iris; svmpathetic irritation and inflammation may 

 follow. 



(2) Exposures. 



(a) To bright light. 



Eclipse blindness is an affection of the macular region of 



the retina from exposure to direct sunlight. The changes 



are probably of a chemical nature brought about by the 



ultra-violet rays. 

 Night blindness occurs in badh' nourished individuals from 



exposure to indirect sunlight unaccompanied by any 



ophthalmic changes. The condition may be due to 



failure of the visual purple which has been bleached by 



the bright light. Bright light reflected from the snow 



will also cause blindness. 

 Erythropsia. A red vision due to bright reflected light. It 



usually occurs in persons whose lenses have been removed. 



The cause is uncertain, it is possibly due to hyperaemia 



of the retina. 

 Cataract. This is common where there is much reflected 



light. Arc lights will cause it. The condition is common 



in glass-blowers. 

 Sponge-fisher's Asthenopsia. This is an hyperaesthetic 



condition caused by the scintillation of sunlight upon the 



water. 



