Smith & Pokorny (1975) protan and deutan data

Data key


  1. Wavelength (nm)
  2. log Protan spectral sensitivity
  3. log Deutan spectral sensitivity


Mean data from 5 protanopes and 4 deuteranopes taken directly from Fig 3 of Smith & Pokorny (1975) and converted to quantal units.

They are flicker detection thresholds for 25-Hz, 2-deg diameter targets of variable wavelength presented in the center of a violet background field. For details see Smith & Pokorny (1975).


Smith, V. C., & Pokorny, J. (1975). Spectral sensitivity of the foveal cone photopigments between 400 and 500 nm. Vision Research, 15, 161-171.