Colour Vision Deficiency
Do you have difficulty telling if something is blue or yellow, and red or green? Do other people sometimes let you know that the colour you think you are seeing is wrong?
If so, these are primary signs of what is called colour vision deficiency, also known as colour blindness.
Colour blindness is not a form of blindness at all, but rather a defect in the way you see colours. If you are colour-blind, you have difficulty distinguishing certain colours, such as blue from yellow or red from green. It is an inherited condition that affects males more frequently than females. An estimated 8 percent of males and less than 1 percent of females have colour vision problems¹.
Red-green colour deficiency is the most common form of colour blindness
Much more rarely, a person may inherit a trait that reduces the ability to see blue and yellow hues. This blue-yellow colour deficiency usually affects men and women equally
2. Wong, Bang. "Color blindness." Nature Methods, vol. 8, no. 6, 2011, p. 441. Accessed 6 Aug. 2020.