EYE DISEASES PROPER 



1995 



affected area shows the mark of a bite, and may perhaps be due to 

 an ant, perhaps of the genus Monomorium Mayr, 1855. 



Congenital Defects. 



These are by no means uncommon in the tropics, and our experi- 

 ence includes cases of apparent anophthalmus or microphthalmus, 

 coloboma, and albinism. 



Colour Blindness. 



This is of importance, and natives who are to be employed as pilots 

 or on railways should be examined as to their power of distinguishing 

 colours; and, indeed, if this has been neglected, it is advisable to 

 examine the ex:isting employes, as the results of such examinations 

 are sometimes surprising. In testing, only the Eldridge-Green 

 lamp and method should be used. 



Errors of Refraction. 



A subject which has begun to attract a considerable amount of 

 attention is the condition of the eyes of native children in the more 

 modern and higher class native schools, as regards errors of refrac- 

 tion; but the medical inspection of native schools in the tropics is 

 at present neglected, though the children suffer from what may be 

 termed book hunger, and so strain their eyes excessively. 



Foreign Bodies. 



In addition to the usual foreign bodies met with in the Temperate 

 Zone, small flies are apt to get into the eye in the early evening, 

 and some of these are very irritating, and may cause congestion; 

 or, by introducing micro-organisms, conjunctivitis. Chalmers and 

 Marshall record the finding of a small ant, Monomorium hicolor var. 

 nitidwenire, firmly fixed by its jaws on to the ocular conjunctiva in 

 a person in Khartoum. 



Pterygium. 



In this disease the pinguecula, being irritated, spreads on to the 

 cornea, and carries the conjunctiva with it, thus giving rise to 

 triangular folds extending from the ocular conjunctiva to the cornea 

 on the inner or outer aspects of the eye. It is very common in the 

 tropics, especially among coolies in Indo-China. 



The treatment is removal. 



Hypersemia of the Conjunctiva. 



This is extremely common, being caused by the glare of the sun 

 or by the dust, especially in sandy regions, and is especially apt 

 to occur in persons who have some slight, and perhaps unnoticed, 

 error of refraction. It is also more liable to occur in persons who 

 have some congestion of the naso-pharynx, and is one of the symp- 

 toms of rhinitis spastica vasomotoria. Usually the symptoms are 

 but slight, but the eyes are inclined to water; this is aggravated 



