76 



COLOUR VISION 



Fig. 29 shows the fields with 



90 -E- 



105 



red 



yellow 

 green 

 blue 



670-5 



589-2 0-21 foot-candle 



530 



460-3 



60 



- E-90 



165 



Fig. 29. The fields of vision for spectral colours with low illumination (D light -0-21 foot- 



candle at the screen). (Abney.) 



