Color 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 color you think you are seeing is wrong?

If so, these are primary signs of what is called color vision deficiency, also known as color blindness.
Color blindness is not a form of blindness at all, but rather a defect in the way you see colors. If you are color-blind, you have difficulty distinguishing certain colors, 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 color vision problems¹.
Red-green color deficiency is the most common form of color blindness.
Much more rarely, a person may inherit a trait that reduces the ability to see blue and yellow hues. This blue-yellow color 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.
