What is green colour blind?

Question

50% (3/6) of my uncles (mums side) are colour blind. My family and i have always thought i had it so we got it checked about 2 or 3 years ago. They said i was green colour blind. I managed to get trough most of the tests ok. The one i had the trouble with was the numbers made out of green dots with other coloured dots around them. Anyway... What is green colour blindness because when my friends ask me what colour something is i always get it right and i have never gotten it wrong when my friends have asked so tell me what is it and how come this happens

Answer 1

The retina is made up of "rods and cones". The rods are for night vision (not color) and the cones allow you to see color when there is light. Each cone contains a light sensitive pigment which helps you see colors properly. In your case, your genes contain a slightly incorrect coding instruction for one or more of the pigments in the cones you use. This slightly shifts the colors you see. You have a mild case.

I'm guessing this is the one you have:

Deuteranomaly (five out of 100 males):
The deuteranomalous person is considered "green weak". He is poor at discriminating small differences in hues in the red, orange, yellow, green region of the spectrum. He makes errors in the naming of hues in this region because they appear somewhat shifted towards red for him. Deuteranomalous individuals do "not" have the loss of "brightness" problem.

From a practical stand point though, many deuteranomalous people breeze through life with very little difficulty doing tasks that require normal color vision. Some may not even be aware that their color perception is in any way different from normal.

Answer 2

Red, green colour blindness is usually inherited. It occurs in about 8 per cent of males and only about 0.4 per cent of females. This is because the genes that lead to red–green colour blindness are on the X chromosome. Males have only one X chromosome and females have two. The son of a woman who carries the gene has a 50 per cent chance of being colour blind. The mother is not herself colour blind because the gene is recessive. That means that its effect is suppressed by her matching dominant normal gene. A daughter will not normally be colour blind, unless her mother is a carrier and her father is colour blind. Only five per cent of people who are colour blind have blue colour blindness. This is equal in males and females, because the genes for it are located on a different chromosome. However, colour blindness is not always inherited. It can also be due to a change in the chromosome during development.


Color blindness results from an absence or malfunction of certain color-sensitive cells in the retina. The retina is the nerve layer at the back of the eye that converts light into nerve signals that are sent to the brain. A person with color blindness has trouble seeing red, green, blue, or mixtures of these colors.