The most common form of color blindness is the inability to distinguish between:

The most common form of color blindness is the inability to distinguish between:

• A. Blue and yellow
• B. Red and green
• C. Black and white
• D. Purple and orange

Answer: (B)

Red-green color blindness is the most common form. This happens because the cones in the eye that detect red and green light are the most likely to be altered or to send signals that overlap, making red and green look similar. Because color vision uses three types of cones, losing or mixing the signals from the red (long-wavelength) and green (medium-wavelength) cones makes distinguishing those two colors difficult in many lighting conditions. It’s also usually inherited on the X chromosome, so it appears more often in men than in women. So people with this condition typically mix up reds and greens but can still see blues and yellows, and they can usually tell black from white. The other color-blindness patterns are much rarer and involve different color pair confusions or a complete lack of color perception.

Red-green color blindness is the most common form. This happens because the cones in the eye that detect red and green light are the most likely to be altered or to send signals that overlap, making red and green look similar. Because color vision uses three types of cones, losing or mixing the signals from the red (long-wavelength) and green (medium-wavelength) cones makes distinguishing those two colors difficult in many lighting conditions. It’s also usually inherited on the X chromosome, so it appears more often in men than in women.

So people with this condition typically mix up reds and greens but can still see blues and yellows, and they can usually tell black from white. The other color-blindness patterns are much rarer and involve different color pair confusions or a complete lack of color perception.