808 



PHYSIOLOGY. 



Red greenish blue. 

 Orange Prussian blue. 

 Yellow indigo-blue. 



Greenish yellowviolet. 

 Green purple. 



Green alone has no complementary color in the spectrum, 

 gives a white color with the compound color purple. 



It 



Fig. 358. Diagram Illustrating Irradiation. (STIRLING.) 



If this diagram is held some distance from the eye, especially if not exactly 

 focused, the white dot will appear larger than the black, though both are of 

 exactly the same size. 



Irradiation. This is a phenomenon which is observed when 

 looking at a strongly illuminated object upon a dark background; 

 the object appears larger than it really is. Thus, of two rings of 

 equal size, one white on black, the other black on white, the former 

 appears larger than the latter. Irradiation is due to imperfect 

 accommodation. Here the margins of an object are projected upon 



Fig. 359. Diagram to show (1) the primary position of the right 

 eye; (2) the eye turned upward and inward, and (3) downward and 

 outward. ( BALL. ) 



er, External rectus. ir, Internal rectus. so, io, Superior and inferior 

 oblique, sr, ifr, Superior and inferior recti. 



the retina in circles of diffusion and the brain tends to increase the 

 ill-defined margin to those parts of the visual image which are most 

 prominent in the image itself. What is bright seems larger and 

 overcomes what is dark. Black clothes make one appear to be much 

 smaller than light clothes. A short person would look taller, and a 

 fat person would look thinner, dressed in vertical stripes. 



