What Is Color Blindness?
Color blindness occurs when you are unable to see colors in a normal way. Most commonly, color blindness (also known as color deficiency) happens when someone cannot distinguish between certain colors, usually between greens and reds, and occasionally blues.
In the retina (the light-sensitive tissue lining the back of the eye), there are two types of cells that detect light: rods and cones. Rods detect only light and dark and are very sensitive to low light levels. Cone cells detect color and are concentrated near the center of your vision. There are three types of cones that see color: red, green and blue. The brain uses input from these three color cone cells to determine our color perception.
Color blindness can occur when one or more of the color cone cells are absent, nonfunctioning, or detect a different color than normal. Severe color blindness occurs when all three cone cells are absent, and mild color blindness occurs when all three cone cells are present, but one cone cell functions abnormally to detect a different color than normal.
There are different degrees of color blindness. Some people with mild color deficiencies can see colors normally in good light but have difficulty in dim light. Others cannot distinguish certain colors in any light. The most severe form of color blindness, in which everything is seen in shades of gray, is uncommon. Color blindness usually affects both eyes equally and remains stable throughout life.
Color blindness is usually something that you have from birth but it can be acquired later in life. Change in color vision can signify a more serious condition. Anyone who experiences a significant change in color perception should see an ophthalmologist (Eye M.D.).
Facts about Color Blindness
Color blindness can be hereditary. If a father suffers from it, his son has a chance of being color blind as well. However, it can also be caused by eye diseases, aging or retina damage.
There are three types of color blindness – one type makes it difficult to distinguish between red and green, the second type makes it difficult to distinguish between blue and yellow, and a third type is actually complete color blindness in which the eye cannot detect any colors at all.
Color blindness is not gender blind. In fact it is much more common among men. Red-green color blindness affects 10% of males in the United States, while only 0.5% of women are affected. 99% of all people with color blindness have red-green color blindness.
Blue-yellow color blindness is rare and affects between 1 in 15,000 and 1 in 50,000 people. Both men and women are affected equally.
Monochromacy is the name for total color blindness. It affects about 1 in 30,000 people. Unlike people with red-green or blue-yellow color “blindness,” people with monochromacy do not see any color at all, only varying shades of black, white, and gray.
The difference between red, green, and yellow traffic lights can be hard to distinguish for colorblind drivers. In Bulgaria, Romania, and Turkey colorblind people are prohibited from driving.
Dogs, cats and rabbits see mostly gray. Monkeys have strong color vision while bees and butterflies have superior vision and can see colors humans canâ€™t even see.
Goldfish are the only animal that can see infrared and ultraviolet light and they have the largest range of color vision so far discovered in any animal.
People with color blindness usually dream in the same limited colors they see in waking life.
Colorblind people often have difficulty with foods. They have trouble telling if a piece of red meat is cooked or raw, they can’t tell whether a banana is yellow or green, and they can’t see any difference between a green, unripe tomato and a ripe, red one.
Not a lot of people, but some, suffer from a rare form of color blindness called unilateral dichromacy which means they have one normal Seeing Eye, and one color blind eye.