# How common is colour-vision deficiency (CVD), who is affected, and why do open sources quote different percentages?

- id: art_01M5MT9MMEB5V5Y46Z4S8YS172
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T12, T17, T18 · tags: none
- updated: 2026-10-23T16:42:51.912Z
- url: https://veyrul.com/articles/art_01M5MT9MMEB5V5Y46Z4S8YS172

Open sources agree on the order of magnitude for red-green CVD: about 8% of men and about 0.4-0.5% of women of European ancestry, lower in men of East Asian and African ancestry. They disagree on the non-European figures (Birch 4-6.5% for Chinese and Japanese men; Machado et al. Table 1 gives 4.2% Asian and 2.6% African; Okabe and Ito give 5% and 4%), and 'around 8-10% of males' in Game Accessibility Guidelines is a design-guideline rounding that adds other conditions. A design brief should cite the population and source of the figure, not a single global percentage.

Open sources agree on the order of magnitude for red-green CVD: about 8% of men and about 0.4-0.5% of women of European ancestry, lower in men of East Asian and African ancestry. They disagree on the non-European figures (Birch 4-6.5% for Chinese and Japanese men; Machado et al. Table 1 gives 4.2% Asian and 2.6% African; Okabe and Ito give 5% and 4%), and 'around 8-10% of males' in Game Accessibility Guidelines is a design-guideline rounding that adds other conditions. A design brief should cite the population and source of the figure, not a single global percentage.

Curator qualifications: All four figures verified. The non-European discrepancy is genuine and source-dependent. GAG's '8-10% of males' is an unsourced round-up of the European figure.

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=22472762&retmode=xml",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://lume.ufrgs.br/bitstream/10183/27630/1/000751721.pdf",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://web.archive.org/web/20210803155953id_/https://jfly.uni-koeln.de/color/",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://www.nature.com/articles/s41467-020-19160-7",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://gameaccessibilityguidelines.com/ensure-no-essential-information-is-conveyed-by-a-fixed-colour-alone/",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://www.colourblindawareness.org/wp-content/uploads/2016/07/BBC-Trust-finds-in-favour-of-colour-blind-viewers-contact-details-amended.pdf",
      "note": "abstract; Table 1; intro; guideline"
    },
    {
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12385717/",
      "note": "abstract; Table 1; intro; guideline"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] Open sources agree on the order of magnitude for red-green CVD: about 8% of men and about 0.4-0.5% of women of European ancestry, lower in men of East Asian and African ancestry. They disagree on the non-European figures (Birch 4-6.5% for Chinese and Japanese men; Machado et al. Table 1 gives 4.2% Asian and 2.6% African; Okabe and Ito give 5% and 4%), and 'around 8-10% of males' in Game Accessibility Guidelines is a design-guideline rounding that adds other conditions. A design brief should cite the population and source of the figure, not a single global percentage. · locator: abstract; Table 1; intro; guideline · source: https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=22472762&retmode=xml

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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