9D44

ICD-11 MMS 2026-01

Impairment of colour vision

Description

Colour vision refers to the ability to distinguish colour differences. True colour “blindness” is extremely rare. Most colour vision deficiencies are minor, and congenital, with X-linked recessive inheritance (more prevalent among men). Some drugs and optic neuritis may also cause colour vision deficiencies.

Index terms

  • Impairment of colour vision
  • achromatism
  • achromatopsia
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  • acquired colour blindness
  • acquired colour vision deficiency
  • colour blindness
  • colour vision deficiency
  • complete colour blindness
  • congenital colour blindness
  • monochromatism
  • protan defect
  • total colour blindness
  • Trichromatism anomaly
  • Protanomaly
  • Deuteranomaly
  • deutan defect
  • Protanopia
  • Deuteranopia
  • Monochromatopsia
  • Tritan defect
  • Tritanopia
  • Tritanomaly
  • Red-green colour blindness
  • Reduced red-green discrimination
  • Reduced red-green vision
  • Dichromatopsia

Inclusions

  • achromatopsia
  • acquired colour vision deficiency
  • colour blindness

Exclusions from above levels

  • 01 – Certain infectious or parasitic diseases
  • 05 – Endocrine, nutritional or metabolic diseases
  • 18 – Complications of pregnancy, childbirth and the puerperium
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  • 19 – Certain conditions originating in the perinatal period
  • 22 – Injury, poisoning or certain other consequences of external causes
  • 8A21.0 – Posterior cortical atrophy

Sibling codes

  • 9D41 – Impairment of visual field
  • 9D42 – Patterns of visual field impairment
  • 9D43 – Impairment of contrast vision
  • 9D45 – Impairment of light sensitivity
  • 9D46 – Impairment of binocular functions
  • 9D7Y – Other specified impairment of visual functions
  • 9D7Z – Impairment of visual functions, unspecified

Foundation entity

Impairment of colour vision – http://id.who.int/icd/entity/2028524981

Allowed postcoordination axes

Part of: 09: Diseases of the visual system