Color+Blindness

=//__COLOR BLINDNESS__//= By:Alison and Olivia

To the surprise of many people, a color blind person can see colors. There are very few color blind people who can see no color at all. Color blindness is a hereditary disease. It can either be caused by a disease in the optic nerve or it can be passed genetically. Color blindness is a sex linked trait. It is a trait controlled by a recessive allele. A mother can pass the disease to all of her children, but it is most commonly passed from mother to son. A father, on the other hand, can only pass the disease to his daughter. In a male cell, only one recessive allele is needed to form a color blind male. A female needs 2 recessive alleles making it harder for females to become color blind. When a person is born with this disorder, the effects are so mild that they sometimes don't even know that they are color blind until they take a color blind test. The two types of color blindness are red/green color blindness and blue/yellow color blindness. Red/green color blindness is the most common type of color blindness. It means that people have trouble seeing reds and greens. Blue/yellow color blindness is less common but it is not as rare as complete color loss.
 * DESCRIPTION**

+=Normal Vision (Dominant) o=Color Blindness (Recessive)**
 * Sex-Linked Genes Located on X Chromosome:
 * **Sex** || **Color-blind** || **Normal Vision** ||
 * **Male** || **XoY** || **X+Y** ||
 * **Female** || **XoXo** || **X+X+ X+Xo** ||

To a person with red/green color blindness, apples will look like this.

Color blindness may be partial, affecting only some colors. It also may be complete, affecting all colors, which is very rare. If color blindness is complete, the person with the color vision problem may have other eye problems as well. If someone is born with color blindness, it does not usually lead to additional vision loss, but his or her vision can be less sharp if color blindness exists. That is why color blindness can keep people from having certain jobs, like being an airplane pilot, a ship captain, or a police officer. People who are red/green color blind have trouble distinguishing the colors of a traffic light.
 * EFFECTS**

In our eyes we have photoreceptors, or cones, located in our retinas. The photoreceptors are the part of our eyes that allow us to see color. The photoreceptors contain pigments in different colors. We have red, green and blue pigments. When one or more of these pigments are missing, we become color blind. The lack of pigment in a person's eyes can either be passed genetically or caused by disease. That is how people become color blind. A person with normal color vision would see strawberries like this. A person who is red/green color blind would see strawberries like this.
 * CAUSE**

Color Blindness is a disease without a treatment or cure. People with mild color vision problems learn to connect colors with certain objects and are usually able to see color as everyone else does. However, they are not able to appreciate color in the same way as those with normal color vision. Some people can wear glasses or contacts that will help them see colors more easily but will not fully cure their disease. Tinted contacts like these help with people's color vision.
 * TREATMENT**

Are you color Blind? Take the test to find out http://www.toledo-bend.com/colorblind/Ishihara.html

1) Do you think that it is fair for color blind people to have job restrictions? Why or why not? 2) Do you think it is better for a person to check if they are color blind when they are a child rather than when they are an adult? Why or why not? 3) What causes color blindness and how is it passed? 4) What color pigments are in our eyes and which pigments are most common to be absent?
 * DISCUSSION QUESTIONS**

Waggoner, Terrace L. "About Color Blindness" __Colors for the color Blind__. 8 May 2007, [|http://www.toledo-bend.com /colorblind/aboutCB.html]
 * RESOURCES**

Wade, Alex. "Can you tell red from green?" __Vischeck.__ 8 May 2007, [|http://www.vischeck.com/info /wade.php]

"Color Blindness" __Mama's Health.com.__ 8 May 2007, [|http://www.mamashealth.com/eye /color.asp]

"Eye conditions" __St.Luke'sEye.com__ 8 May 2007, http://www.stlukeseye.com/conditions/colorblindness.asp

Cronkite, Donald. __Science Explorer, Cells and Heredity__. Upper Saddle River, New Jersey: Prentice Hall, ©2002.

"Color Blind Chart" __Color Blindness and Baldness in people__. 15 May 2007, [|http://www.waynesword.palomar.edu/ colorbl1.htm]