Color Blindness Part I




Justlike any other organism, human beings are also made up of cells. Eachcell contains a pair of genes, which are packed into protein parcelsknown as chromosomes. A person inherits these genes from bothparents, one from the father and the other from the mother.Unfortunately, some genes function abnormally causing geneticdisorders. Biologically, genes are passed from one generation to thenext hence, genetic disorders. Altered gene or combination of genescauses the genetic disorder. There are four groups of geneticdisorders namely, chromosome abnormalities, single gene disorder,multifactorial disorder, and mitochondrial disorder (Levineand Walls, 2013).The main ways of inheriting genetic disorder are x-linked recessive,x-linked dominant, autosomal recessive, and autosomal dominant. Up todate, there are over eighty genetic disorders. For my case, colorblindness is the most potential genetic disorder that can affect me.This paper introduces color blindness, outlines it major signs andsymptoms, and its mode of inheritance.

ColorVision Deficiency (CVD), commonly known as color blindness, is theinability to see or perceive color differences in a normal lightingcondition. It is a common gene disorder that is passed from parentsto their children. The X chromosome gene is responsible for thiscondition hence, the condition affects men more than women.According to research, 8% of men and 0.5% of women are affected withcolor blindness worldwide (Levineet. al., 2013).Color blind people see clearly just like other people, but theycannot fully differentiate colors. The majority of color blindinherit the condition from their mothers, who themselves are notcolor blind, but carriers. However, the effect of color blindness canbe severe, moderate, or mild depending with the defect. If thecondition is hereditary, the condition remains the same throughoutit does not get worse or better.

Signsand Symptoms

Asthe name suggests, the common symptom of color blindness isdifficulties in differentiating colors. For instance, one may fail todistinguish between red and green colors or blue and green. In somerare cases, people with the color disorder have rapid eye movement,while others only see black, white, and gray colors. According toDovidio,Gaertner, and Saguy (2015),people with color disorders are sensitive to bright colors, have anoutstanding sense of smell and night vision.

Modeof Inheritance

Thereare three types of inherited color blindness monochromacy,dichromacy, and anomalous trichromacy (Sanjek,2014).Monochromacy, also total color blindness, is the inability todistinguish color. It is caused by cone absence or defect. A personsees things as if they are only in black in white colors. Dichromacyoccurs when a basic color mechanism is not functioning or absent.However, it is more moderate compared to monochromacy. On the otherhand, anomalous trichromacy occurs when one of cone pigment isaltered.

Aneye has three types of cone cells. Each type sense blue, green, orred light. Inherited color blindness occurs when one does not haveone of this cone cells, or it is functioning correctly. A motherpasses red/green color blindness to her son or daughter through the23rdchromosome (Albrecht,2010).The 23rdchromosome is composed of two parts, the X and Y chromosome for amale and two X chromosome for a female. Only the X chromosome canhave a faulty gene, which causes color blindness. Therefore, a femaleis color blind when a faulty gene in present in both her Xchromosomes. On the other hand, a male is color blind when a faultygene is present in his X chromosome. According to Wong(2011),when a female has only one gene that is color blind, she is not acolor blind herself, but she is a carrier. Biologically, if the womanis to give birth, she will donate one of her X chromosomes. If the Xchromosome gene is not faulty, the son will not be color blind, butit is faulty, then, the son will be color blind. A father cannot passa color blind gene to his son even though he is color blind becausehe donates Y chromosome and not X chromosome to the son. On the otherhand, a daughter will be color blind if the mother is a carrier, andthe father is a color blind. The mother has to pass the faulty geneto the daughter. However, if the father is not a color blind,likewise, the daughter will also not be color blind, but a carrier.This why males are more likely to be color blind than women.

Tomake a conclusion whether one is a color blind, one should be awareof his or her parent status (McIntyre,2002).If the mother is a color blind carrier, and the father is colorblind, there a high possibility that one will be color blind.Therefore, family history is significant in determining thepossibility of color blindness.

Whilegathering the information about my family history on color blindnessissue, I realized some people were not even aware of the condition.This held back by research and I took a longer time before making aconclusion. Hence, it was difficult to tell whether my conditioncould be hereditary. Based on my knowledge about color blindness, Iwould tell my children about the condition, as well as explain thecauses.


Atthe KU library, I search for the reference through the advancedsearch. I used combinations of words and single words to search forthese references. For instance, I searched the color and blindnesswords together or color blindness separately. The search where I usedthe combination of words gave many results that is, many referencesrelated to the topic. I also refined to narrow my results to get areference that is more related to my topic.


Albrecht,M. (2010). Color blindness.&nbspNaturemethods,&nbsp7(10),775-775.

Dovidio,J. F., Gaertner, S. L., &amp Saguy, T. (2015). Color-Blindness andCommonality Included but Invisible?.&nbspAmericanBehavioral Scientist,0002764215580591.

Levine,K. R., &amp Walls, F. (2013).&nbspAllabout color blindness: A guide to Color Vision Deficiency for kids(and grown-ups too).Huntington, NY: Halesite Press.

McIntyre,D. A. (2002).&nbspColourblindness: Causes and effects.Chester: Dalton Publishing.

Sanjek,R. (2014).&nbspEthnographyin today`s world: Color full before color blind.Philadelphia: University of Pennsylvania Press.

Wong,B. (2011). Points of view: Color blindness.&nbspNaturemethods,&nbsp8(6),441-441.