Have you ever thought about what it would be like to see the world in different colors? When someone is color blind, it means that his or her eyes don't see colors the same way as most other people.
Color blind people almost always see some colors, but they usually have trouble telling the difference between certain shades and might have some colors that they can't see at all. Color blindness is most often inherited, meaning it's passed on in families from parents to their children.
In order to see color, our eyes have three types of cells. Each type senses different shades of one certain color: red, green, or blue. Working together, they allow us to see a larger combination of colors. (Such as red and blue making purple.) When a person is color blind, it means that he or she does not have one or more of these special cell types, or that their cells for that color don't work. This means that person can't see all or some shades of that color, or any other color that contains the missing color. Certain colors (like red and green, or blue and yellow) come out looking the same to the color blind person.
Luckily, color blindness isn't a big problem for most people. It might just mean they need more help picking out two socks that match!
Doctors often give kids a "color test" to check for color blindness. Usually a test like this has a number or a shape that is a certain color, contained within a shaded area that is another color. Someone who is color blind to red and green wouldn't be able to see a red number "8" drawn within a green background!Have you ever taken a color blindness test? You could try to make your own, and then try it out on some of your friends and family!
Occasionally, a person will not be able to see any colors at all. This is known as achromatopsia, but it's is very, very rare.