Congenital colour blindness is an inherited change in colour vision present from birth, usually affecting both eyes equally and remaining stable throughout life. Most affected individuals have difficulty distinguishing certain shades rather than seeing in black and white.
Types
The commonest forms are red-green deficiencies caused by altered cone pigment genes on the X chromosome, leading to reduced sensitivity to either red or green wavelengths. Rarer types involve blue-cone or more complex cone function abnormalities.
- More frequent in males because of X-linked inheritance
- Often discovered in childhood during colour-based tasks or screening
- Visual acuity is usually normal in simple deficiencies
- Standard colour vision tests classify the specific type and severity
Management
There is no cure for the underlying genetic change, but many people adapt well by learning alternative cues. Educational and occupational advice can ensure that colour vision limitations are recognised and accommodated.
- Colour-coded information may need additional shapes, labels, or patterns
- Specialist lenses may enhance contrast for some users, though they do not restore normal colour vision
- Family members may be offered screening because of inheritance patterns
- Awareness helps prevent misunderstandings about performance in colour-based tasks
