388 



nutting: chromatic aberration of human eye 



Tests were made for residual chromatic spherical aberration 

 (departure from Gauss condition) by placing half of a half-tone 

 screen over the test slit. The writer could detect no residual in his 

 own eye in the region from 500 to 650. Beyond 700 in the red 

 and beyond 480 in the blue it is noticeable, while at 406 in the 

 violet it amounted to fully twenty times the normal diffusion. 

 L. A. J. agreed with the writer, but L. E. J. could detect little loss 

 of definition at 406. 



+.025 







-.025 



-.050 



-^ . — ■ ■! ■ " ■■■■ ■ ' ■ — 



WATER 



L.A-J. 



P.G-.N. 



L.E,J. 



M.B.H. 



J.D.H. 



C.H.B. 



40 



50 



60 

 Fig. 2 



70 



80 



I wish to record my indebtedness to Mr. Eastman and Dr. 

 Mees for apparatus and to those of my assistants who served as 

 subjects. 



