{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://openvisual.org/schema/cvd/1.0",
  "title": "OVS: Color Vision Deficiency",
  "description": "Altered color discrimination — congenital (red-green, blue-yellow) or acquired (optic nerve, retinal disease). Modeled using Brettel matrix transformations.",
  "allOf": [
    { "$ref": "https://openvisual.org/schema/symptom-base/1.0" },
    {
      "type": "object",
      "required": ["subtype"],
      "properties": {
        "ovs_type": { "const": "ovs:cvd" },
        "subtype":  {
          "type": "string",
          "enum": ["protanopia", "deuteranopia", "tritanopia", "achromatopsia"],
          "description": "protanopia: red-blind. deuteranopia: green-blind. tritanopia: blue-yellow. achromatopsia: complete colorblindness."
        }
      }
    }
  ]
}