Colour blindness

Key facts Colour blindness is when you can’t see certain colours in the usual way. People who are colour blind may confuse some colours, may not see some colours as brightly as people with normal vision or they may not see colours at all. Colour blindness is usually inherited and is there from birth, but it can also arise later in life from damage to the brain or eyes. Your doctor or optometrist can use different types of colour vision tests, such as the Ishihara test, to help diagnose colour blindness. What is colour blindness? Colour blindness is a condition