Color blindness

📖 In short

Color blindness is a condition in which a person can't tell some colors apart the way most people do. They may see red and green as almost the same. It's also called “daltonism” after a scientist who had it and wrote about it.

🤩 Did you know?

Color blindness is more common in boys than in girls.
People are usually born color-blind rather than becoming so suddenly.
Most color-blind people see lots of colors, not just black and white.
The word “daltonism” comes from the English scientist John Dalton.

🔎 Find out more

🌟 Cones in the eye

Inside the eye are special cells called cones that let us see colors. Most people have three kinds: one for red, one for green and one for blue.

🔍 What happens in color blindness?

If one kind of cone doesn't work well, the person finds it hard to tell some colors apart. The most common kind is trouble telling red from green.

💡 The colored-dot test

Doctors check for color blindness with cards full of colored dots with a number hidden among them. People who see colors well can read the number, and color-blind people may not see it.

🎯 An ordinary life

Color-blind people live completely ordinary lives. They learn simple tricks, like reading a traffic light by where the light is: red at the top and green at the bottom.