Color blindness is having trouble distinguishing some colors from others. They may not be able to tell the difference between red and green or blue and yellow. This is usually not life altering. You can usually still drive, work, and live normally.

Some people are color blind and don’t know it. For example, they know tree leaves are green, so they think the color they see is “green.” The types of color blindness are categorized as Red-Green color blindness, Blue-Yellow color blindness, and Complete color blindness.

There are several tests that professionals can use to determine if you are color blind. The most commonly known is the Ishihara Test. Usually this test involves recognizing a number or set of numbers in a field of colored dots of different colors. If you have trouble seeing the numbers then you likely are color blind.

“It very minimally impacts everyday life,” says Jane C. Edmond, MD, an ophthalmologist at Texas Children’s Hospital.

The term itself is a little misleading. With rare exception, people who are color blind don’t live in a colorless world. They see most colors clearly. Some people with red-and-green color blindness wear special contact lenses!