What is colour blindness?
Colour vision defects are almost always inherited, although some forms can be acquired condition as a result of some diseases or injuries.
In the general population, about 8% of males and 0.5% of females have colour vision deficiencies. Almost all colour deficient people do see a large range of colours but they will have difficulty identifying particular colours. The most common defects lead to confusing certain shades of red and green for example
As children, few of these people will be aware that they have a colour vision deficiency but the detection of these problems is important, especially when career choices are affected.
Examples of Ishihara Colour Vision Examination Plates: