338 



THE SENSES 



1X0 



135 



SO 



165 A 



180' 



105 



225 



A perimeter chart with records for a right eye: B, blind spot. The unshaded portion is the 

 field of clear vision for white light. The fields for yellow, blue, red, and green light respectively 

 are indicated by the variously broken lines. It is only within the inner circle of the chart that 

 vision is direct and perfect. (Krapart.) 



FTG. 192 



*\ Nerve 



Diagram showing relative positions of the eye's refractive media and the reduced refracting 

 medium (PPP). Drawn to scale and five times the natural size. (Hall.) 



