What causes colour blindness?


COLOUR BLINDNESS or colour vision deficiency (CVD) affects approximately 1 in 12 men and 1 in 200 women in the world.
Colour blindness is usually a genetic or hereditary condition. Red/green and blue colour blindness is usually passed down from your parents. The gene which is responsible for the condition is carried on the X chromosome and this is the reason why many more men are affected than women. The vast majority of people with a colour vision deficiency have inherited their condition from their mother, who is normally a ‘carrier’ but not colour blind herself.

The effects of colour vision deficiency can be mild, moderate or severe depending upon the defect. If you have inherited colour blindness, your condition will stay the same throughout your life – it won’t get any better or worse.