Noun

Definition: a lack of something that is needed : the state of not having enough of something necessary.

Source: http://www.merriam-webster.com/dictionary/deficiency

For my Psycology test i had to studty theories and terms. One of the terms was colorblind. the definition was: A deficiency in the ability to distinguish among colors. I know what was colorblind but i didnt know the word deficiency. To have a better understanding of the definition i wanted to know what the word deficiency ment so i searched it up.

Deficiency is another word for lack of something needed, so this helped understand more the definition of the word colorblind. Since the person is lacking in the ability to see colors cause of less cones they have, it’s more likely of being colorblind.