234 THE WONDERFUL HOUSE THAT JACK HAS 



This page shows a view of the eye as it would ap- 

 pear if cut into two equal parts, as one might divide 



an apple, and if 

 the flat, cut surface 

 were held up to 

 view. 



By examining it 

 we can see that the 

 eye has three coats, 

 two humors, and a 

 lens. The sides and 

 back of the outside 

 coat, marked scle- 

 rotic but commonly 

 known as the 

 " white of the eye," 

 are strong and opaque and serve as a protection. The 

 front part of the outside coat, the cornea, fits into 

 the sclerotic or white somewhat as a watch crystal is 

 set in its case. It is strong like the white, but differs 

 in being transparent. 



The -second or middle coat contains many blood- 

 vessels and pigment cells. It serves to absorb super- 

 fluous light. The back and sides of this middle coat 

 are called the choroid. Its front part, the iris, gives 

 color and beauty to the eye, and is the curtain that 

 softens the light entering it. When babies are born, 

 the iris is usually blue, but it often changes to harmonize 

 with the complexion of the person, a brunette, as a 



Artery 

 Optic nerve 



A Section through the Eyeball. 



