WOKM IN THE EYE. 343 



SYMPTOMS. — The first sign of the worm is a sliglit dimness 

 or milky iaippearance of the cornea, which is due to inflammation 

 caused by the presence of the worm ; and beneath the cornea the 

 parasite may often be seen moving about in the anterior chamber 

 of tiie eye. Not infrequently, while the eye remains moderately 

 clear, the worm suddenly disappears, and then, after some time, 

 comes into view again. In such a case, it inserts itself, for the 

 time being, between the iris and the lens. The fact that simple 

 ophthalmia is accompanied by an inflamgd appearance of the eye- 

 lids, as its first symptom, serves to distinguish it from " worm 

 in the eye," the inflammation of which, unless in very advanced 

 cases, does not extend to the eyelids. The cornea of the filaria- 

 affected eye, generally assumes an evenly distributed dimness, 

 which as a rule, rapidly increases, until the opacity becomes more 

 or less complete. If there be any difficulty in seeing the parasite 

 through the inflamed cornea, the horse should be taken into a 

 dark place, and the eye examined by means of a candle. "When 

 the inflammation of the cornea is in its first stage, it may subside 

 to some extent, and the eye may become clearer on account of 

 the parasite ceasing to irritate the parts by inserting itself between 

 th'3 lens and the iris, and remaining there for some time. There 

 will usually be a slight flow of tears from the eye ; which, however, 

 will (unlike an eye suffering from simple ophthalmia) evince but 

 little intolerance to light. If the filaria is suspected of hiding 

 between the lens and the iris, its presence may be discovered in 

 the manner devised by Mr. Spooner Hart, M.R.C.V.S. Place the 

 patient in a darkish stable, and let the light shine into the 

 affected eye from the front and a little to the side of the head, 

 just above the level of the eye, so as to render the interior of the 

 eyeball luminous, and stand about four or five yards off in the 

 line of the light, when a gigantic worm, moving about inside the 

 eye, will be visible ; never more than one worm being seen in 

 the same eye at the same time. My Indian experience, on this 

 point, is the same as his ; although I have seen a horse in 

 Cambridgeshire, in one of whose eyes I observed several 

 (apparently four or five) filarise moving about. It occasionally ' 

 happens, even > in cases which receive no treatment, that the worm 

 disappears from the eye and leaves no traee behind. The usual 

 ending of untreated cases is that the inflammation caused by the 

 presence of the worm proceeds to such an extent, that the cornea 

 becomes opaque, and the horse loses the sight of the involved 

 eye. 



Respecting the ability of a worm to insert itself between the 

 lens and the iris, in Fig. 140 there is a space shown between these 

 two structures, which has been made merely for clearness' sake ; 



