Do you know much about color blindness? It can make life activities difficult
I only know about one kind of color blindness red-green color blindness.
That can make a lot of things difficult, like buying fruit, reading traffic lights, and picking clothes!
I couldn't imagine being color blind. 
For a lot of people, the issue is minor and people can adapt over time
How many people are affected by color blindness?
That much I do not know, but whoever it affects is stuck since there is no cure for color blindness