104 CATARACT. 



succeeds another until at length those changes become evident in 

 the aspect and magnitude of the pupil which are known to betoken 

 the supervention of cataract ; and until this be completed we may 

 look for returns at longer or shorter intervals of paroxysms of 

 ophthalmia. Nor will, indeed, the maturation of the cataract be 

 in every case followed by a subsidence of inflammatory action, 

 though often, as a sort of crisis, it is seen to have this effect : in 

 many cases, however, have I known the disease still to continue 

 to relapse. Cataract has been known to be the product of a 

 single attack of ophthalmia ; but this is a rare case. 



Mr. W. C. Spooner, V.S., Southampton, informs us, in The 

 Veterinarian for 1840, that he has ''known it supervene within 

 a fortnight from the first attack." 



The Cataract of Ophthalmia consists in a gradual change 

 in the aspect and composition of the lens, and this commonly 

 pervades all parts of the lenticular body at one and the same time. 

 The earliest perceptible alterations in the pupil after one or more 

 attacks of periodic ophthalmia, are, First, unusual irritability ; it 

 contracts quicker and more forcibly on exposure to light than 

 that of a sound eye is known to do, and in consequence becomes 

 actually smaller than the other. Secondl}^, the corpora nigra 

 hang lower down than in health, shading more the superior parts 

 of the pupil. Thirdly, viewed out of the glare of light, while in a 

 state of dilatation, the pupil discloses the lens changed from its 

 natural deep blue colour to that of a French grey. Should the 

 iris contract adhesion with the capsule of the lens while the pupil 

 is in this irritable and contracted state, which is often the case, 

 this small pupil will become permanent, and we shall see nothing 

 indicating confirmed cataract, until some white specks or streaks 

 make their appearance through the aperture. In other cases, some 

 changes take place of a glaucomatous nature, followed by others of 

 an amaurotic tendency, which render the eye tolerant of light; and 

 the result is, dilatation instead of contraction of the pupil, and the 

 conversion of it into an amber-coloured or amber-green-coloured 

 body, which ultimately, as in the other case, turns to a cataract. 

 We read of cataracts being large and small, white, black, green, 

 yello\v, brown or ash-coloured, &c. Such varied descriptions 



