Vision disorders
Colour blindness (colour vision deficiency): signs, testing and support
Colour blindness — also called colour (or color) vision deficiency — means you have difficulty telling certain colours apart. It doesn't cause complete blindness, but it can make some colours hard to identify.
What is colour blindness?
Colour blindness is most often inherited and affects more men than women. Most people with it see colours, but some shades look alike or less vivid.
Signs of colour vision deficiency
- Difficulty telling red from green, or blue from yellow
- Trouble seeing the difference between shades of the same colour
- Colours that look dull or washed out
Can colour blindness be treated?
Inherited colour blindness can't be reversed, but aids such as special glasses and contact lenses, or colour-identifying apps, can help with everyday tasks.
Getting tested
If you suspect colour blindness, or have trouble telling colours apart, talk to an eye care professional for testing and support.
Frequently asked questions
When to go to a hospital instead
Go to the nearest hospital emergency department immediately if you have:
- Sudden loss of vision
- Flashes of light or a shower of new floaters
- Eye injury or chemical splash
- Severe eye pain or a very red, painful eye
- Double vision that comes on suddenly