Impaired ability to distinguish colors on the spectrum.

Most of us see our world in color. We enjoy looking at a lush green lawn or a red rose in full bloom. If you have a color vision defect, you may see these colors differently than most people. There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue-yellow color vision defects and a complete absence of color vision. Most of the time, color blindness is genetic. There is no treatment, but most people adjust and the condition doesn't limit their activities.

Partial or total inability to distinguish one or more chromatic colors.

The absence of or defect in the perception of colors.

Color blindness - or more accurately, poor or deficient color vision - is an inability to see the difference between certain colors. Though many people commonly use the term "color blind" for this condition, true color blindness - in which everything is seen in shades of black and white - is rare.

Colour blindness, inability to distinguish one or more of the three colours red, green, and blue. Most people with colour vision problems have a weak colour-sensing system rather than a frank loss of colour sensation. In the retina (the light-sensitive layer of tissue that lines the back and sides...