COLOR SENSITIVITY OF THE PERIPHERAL RETINA. 25 



color tone had appeared. From the magnitude of the shifting required 

 in any given case, he was able to calculate the relative sensitivity of a 

 given retinal region to the color of the stimulus employed. 



In the following table the foveal sensitivity to each stimulus is taken 

 as a standard ; the sensitivity of points along the nasal meridian is ex- 

 pressed in terms of the standards. * 



This table shows that color sensitivity is keenest at the fovea ; that 

 it decreases gradually toward the periphery, and that the rate of de- 

 crease is different for different colors and for different parts of the 

 retina. Dobrowolsky also found that practice tends to extend the 

 limits of the color zones. During a period of thirteen years, which 

 had for the most part been devoted to spectroscopic experiments, his 

 sensitivity to all colors had increased by about one-half. It is interest- 

 ing to note, however, that this improvement was confined to the eye 

 that had been used in his experiments ; his left (unused) eye showed no 

 increase of sensitivity during this period. 



Albinif had discovered that the "form sense" of the peripheral 

 retina is improved when the peripheral error of refraction is corrected 



^Dobrowolsky, 1. c., S. 23. 



tE. Albini. Delia visione indiretta delle forme e dei colori, Giornale della 

 R. Accademia di Med. di Torino, XXXIV, 1886, pp. 657-675; Sulla visione 

 indiretta delle forme e dei colori, Annali di Ottalmologia, XV, 1887, pp. 482-485. 



