ADVICE TO BUTEES. 57 



eyes are exposed to a strong light, and enlarge again when 

 the horse is brought into a darker situation ; so that if the 

 light is allowed to fall more strongly on one eye than on the 

 other, the former will appear smaller. 



When an imperfection is observed in the eye, it is fre- 

 quently said to arise from a bite, or blow, or from hay seeds 

 falling into it; but, though the seller should positively 

 affirm, this to be the cause of the imperfection, I should 

 always be inclined to doubt it, because experience has 

 taught me that the diseases of the horse's eye almost al- 

 ways arise from internal causes ; that, however trifling in 

 appearance, they are really of a serious nature, and most 

 commonly, even after they have been apparently cured, 

 terminate, sooner or later, in blindness. Too much caution, 

 therefore, cannot be observed in examining this important 

 part. There is a disease, to which the eye is subject, 

 termed "gutta serena," or glass eye, which, although the 

 horse be totally blind in either one or both eyes, it is dif- 

 ficult to be noticed by an inexperienced person, as there are 

 no specks nor any dullness about the eye; in fact, just the 

 contrary ; but, on close examination, if one eye bo affected, 

 you will find the lids somewhat more apart than the other 

 eye, and there will be more of a sort of staring appearance 

 about it, and the eye itself will have a more glossy aspect 

 than natural ; but if both eyes are diseased, you will find 

 greater difficulty in detecting it, as both eyes will then be 

 alike in size and appearance; but you must in this case 

 take notice of the size of the pupil while in the dark, and 

 bring the horse towards the light, and if you see no differ- 

 ence in the size of the pupil, the horse is blind, as the pupil 

 should become smaller when exposed to the light, and, be- 

 sides, the horse will raise his feet a little higher than or- 

 dinary. ' 



