52 



THE EXTERIOR OF THE HORSE. 



alterations. For this purpose the ophthalmoscope may sometimes be 

 used with advantage. Then the animal is taken into broad daylight 

 to see how the eye acts under the influence of the solar rays. To de- 

 termine simply the integrity of vision the following procedure is pur- 



FiG. 21.— Examination of the eye. 



sued : The observer places himself in front of the animal, strikes the 

 side of the face lightly with the hand, and suddenly withdraws it in 

 elevating it to a level with the corresponding eye. The latter, if vision 

 is not impaired, will suddenly close from fear of being struck. If the 

 sight is impaired or lost, the eyelids remain stationary. This manoeuvre 

 is repeated witli the opposite eye. The movements of the hand must 

 not be too forcible, as excessive vibration of the air may even affect a 

 blind eye, particularly in one-eyed horses. If it be desired to examine 



