The main symptom of color blindness is not seeing colors the way most people do. If you’re color blind, you may have trouble seeing:

The difference between colors

How bright colors are

Different shades of colors

Symptoms of color blindness are often so mild that you may not notice them. And since we get used to the way we see colors, many people with color blindness don’t know they have it.

People with very serious cases of color blindness might have other symptoms, too — like quick side-to-side eye movements (nystagmus) or sensitivity to light.