Color-Blindness Test

Color-blindness is the inability to distinguish the differences between certain colors. This condition results from an absence of color-sensitive pigment in the cone cells of the retina, the nerve layer at the back of the eye.
A person with color-blindness has trouble seeing red, green, blue, or mixtures of these colors. The most common type is red-green color-blindness, where red and green are seen as the same color.