4:6 LESSONS IN HORSE JUDGING. 



whole lens is swollen and white like milk. Dis- 

 ease causes 'cataract,' notably that disease in 

 which a patient passes quantities of sugar with 

 his water. Old age produces 'cataract,' by the 

 lens shrinking and altering its proper structure. 



When the ' cataract ' is complete, that is to say, 

 when the whole lens is affected, you see the milky 

 white lens through the pupil, or in other words, 

 the opening called the pupil, instead of being 

 black as midnight, has a chalky or white appear- 

 ance. 



But the 'cataract' may not be complete; that 

 is, only part of the 'lens' may be white and 

 opaque. A 'cataract' may be no larger than a 

 pin's head, and may be situated in any part of 

 the 'lens.' 



30. — To test the lens we use our lighted candle 

 in our darkened stable. The test is called the 

 'catoptric test,' and is very easily applied. You 

 take the candle and place it a little in front of the 

 eye, a few inches from it, when you see three 

 images of the candle-light; one upon the surface 

 of the 'cornea,' one upon the front capsule of the 

 'lens,' (our front watch-glass,) and the third still 

 further back, upon the hindmost capsule of the 

 lens, (our hindmost watch-glass). Now, after 

 you have distinctly found these three images, 

 notice that the tiuo front ones are upright like 

 the candle-flame, but the hindmost image is iip- 

 side doivn. After quite making out this fact, 

 gently move your light from side to side, and 

 you will see that while the two front upright 

 images move in the same direction as the candle. 



