Color blindness is a problem or defect that affected some people to receive some or all the colors, which occurs when the light sensitizing chemicals in the eyes, not working properly. It is a hereditary and congenital disease and its symptoms can vary from one person to another.
People with color blindness, are well, so this is a problem of color vision, or color, and you have a marked inability to distinguish one color or a certain range of it.
Usually there is often inability to distinguish red or green, or blue and yellow hues. There are a variety of color blindness called achromatopsia, in which the only colors that stand out are the black and white, for a lack of cones sensitive retina that fine reception given color to the brain, but often rare.
Symptoms of blindness emphasize that some people have a marked difficulty seeing or define the colors and brightness.
It can also happen that the color blind person, does not distinguish between the shades of the same color or different colors.
Most of the symptoms might be mild, depending on how the patient is aware of its inability to define the colors.