Color Blindness
When
I was a kid in kindergarten, my parents never knew why I got low grade
in identifying the color of crayons. Not until the day I was responsible
for an Open Day project on color blindness in my secondary school did I
noticed that I am one of the 'victim'. Though I was not blamed for the
low grade then, restriction on choosing my job twenty years later frustrated
me somehow.
Color
blindness is an inaccurate term for a lack of perceptual sensitivity to
certain colors. Absolute color blindness is almost unknow. There are three
types of color receptors in our eyes, red, green and blue. We also have
black and white receptors. They are more sensitive than the color receptors,
that is why we have poor color perception in the dark.
Color
blindness comes as a result of a lack of one or more of the types of color
receptors. Most color perception defects are for red or green or both.
About 10% of males have a color perception defect, but this is rare in
females. Red-green color blindness is a result of a lack of red receptors.
Another
form of color blindness -- yellow-blue is the second most common form,
but it's extremely rare. It is also possible to have the color receptors
missing entirely, which would result in black and white vision.
