Achromatopsia 1


A rare form of colorblindness involving complete rod monochromatism which means that that there is no color can be seen and everything appears gray.


  • Head posture against strong light
  • Absence of photopic flicker
  • Very few cones
  • No cones
  • Depigmented cones
  • Cone degeneration
  • Undulatory nystagmus
  • Inability to distinguish colors
  • Visual acuity loss
  • Extreme light sensitivity
  • All objects appear gray
  • Scotopic vision


Mutations in the genes encoding the CNGA3 and CNGB3 subunits of the cyclic nucleotide-gated (CNG) channel of cone photoreceptors have been associated with autosomal recessive achromatopsia


The diagnosis of achromatopsia is based on case history, color vision testing, electrophysiologic examination, and absent or only minor fundus changes.


There is no known treatment.