What is
Color blindness???
It is a genetic disorder that is the inability to distinguish
different colors of the spectrum
It's caused by X- linked mutation in either the long- (L) or
the middle- (M) wavelength-sensitive visual photo
pigments.
People diagnosed with color blindness can see limited range
In a rare condition you can only see shades of gray.
Color blindness is a trait that is only found on the
x- chromosome
Inheritance
Color blindness is usually inherited or passed down from the P
generation to the offspring
It affects more men then women because women have a second
x-chromosome which usually masks the abnormal gene
If the x in the male is recessive than he will display the trait
If the women does have this gene then it can be passed on from the
woman to the child
Cones of color
Someone with normal color vision has receptor cells called cones,
which are located at the retina of the eye
A mixture of red, green, and blue region pigments make up the
various colors that a normal color vision would see
There are 3 types of cones termed:
Red
Blue
Green
These let you see the wide range of color in the spectrum
An abnormality with the cones result in abnormal color vision
Types of Color blindness
Some people can see red/green (protanopia) which is the most
common type of color blindness
Some people have blue color blindness-> which disguises the
colors blue and yellow (trinopia)
This affects both men and women equally because there is no
x-chromosome
Rarest type of color blindness-> achromatopsia
This is where people can only see shades of gray and squint in
regular light
Tritan
Deutan
Normal
Protan
To determine the type of color
blindness they use pigment tests
Deuteranopia: achromatopsia :
Shades of gray
Red/Green
Protanopia:
Red/Green
Tritanopia:
Blue/yellow
Signs and symptoms of
color blindness.
Include trouble seeing colors and brightness of colors in there usual way.
Inability to tell difference between shades of the same colors.
Sometimes people are unaware that they are color blind because symptoms
are so mild
A parent may also notice that there child is color blind when they are learning
there colors
Some times people discover that they are color blind when applying for a job
such as pilot for the navy that requires them to pass a flight physical test.
Cure and treatment for
color blindness
There is no cure for inherited color blindness yet, but
there are some treatments for non-inherited color
blindness.
For example if a cataract is causing a problem with
color vision, surgery may restore normal color vision.
However, there are special contact lenses and
glasses that may help people with color blindness tell
the difference between similar colors.
Research on Color
Blindness.
On the picture above a monkey is taking a color
vision test. Researchers are using gene therapy on
monkeys to try to cure red green color blindness.
After weeks of treatment monkeys could see colors
that they could never see before !
This has lead to many successes using gene therapy
to treat people with inherited retinal diseases. These
results could lead to cures and treatment to color
blindness and eye diseases.
Fun Facts
Some famous people that are color blind are Mr. Roger, Paul
Newman, Bing Crosby and Howie Mandel.
Some groups that are prone to that disease are 8% Caucasians ,
5 %Asians, 4 % African Americans and it is more prone to
males (8%) than females (0.5%).
An English chemist John Dalton was the first to describe the
condition
This is why the scientific name for color blindness is daltonism
Dogs, cats, horses, cows, and most other mammals are color
blind
Bibliography
Fallon, L. Fleming. "Color blindness." The Gale Encyclopedia of Genetic Disorders. Ed. Stacey L. Blachford.
Vol. 1. Detroit: Gale, 2002. 257-260. Gale Virtual Reference Library. Web. 8 Mar. 2012.
“Color blindness.” Complete Home Medical Guide. 2004. eLibrary Science. Web. 8 Mar 2012.
Travers, Bridget. The gale encyclopedia of science volume 2. Detroit Mi: Gale, 1996. Print.
"Color Blindness." Encyclopedia. Today’s Science. Facts On File News Services, n.d. Web. 8 Mar. 2012.
<http://www.2facts.com/article/xco179300a>.
Why are some people color-blind?." A.D.A.M. Life's Greatest Mysteries. 2001. eLibrary Science. Web. 08 Mar
2012.
Kochman, Richard S. "Color Blindness." Encyclopedia Americana. Grolier Online, 2012. Web. 8 Mar. 2012.
"Color vision deficiency ." Genetics Human Reference . National Insitute ofHealth , 5 Mar. 2012. Web. 11 Mar.
2012. <http://ghr.nlm.nih.gov/condition/color-vision-deficiency>.
Mancuso K, Hauswirth W, Li Q, Connor T, Kuchenbecker J, Mauck M, Neitz J, Neitz M. Gene therapy for
red–green colour blindness in adult primates. Nature 461, 784-787 (8 October 2009).