The growth of diseases and disorders has become a prevalent topic throughout the history of mankind. A common example of these maladies is the issue of colorblindness. According to the Merriam-Webster dictionary, colorblindness is defined as being “affected with partial or total inability to distinguish one or more chromatic colors” (Merriam-Webster, Inc., 2012). This genetic trait affects the lives of many living within the world today. “Color deficiency” (A.D.A.M., 2011), known for short as color blindness, is generally classified mainly as a sex-linked genetic disorder. Genetic diseases as a whole are usually considered incurable disorders that are linked to the DNA make-up of the individual. They are created due to a malfunction of the forming of the genetic code such as, not correctly copying the complimentary combination of DNA genetic material during replication and transcription, and failing to accurately completing the process of creating RNA during translation.
Outside of DNA and RNA production, genetic disorders can be formed by other methods including adding or subtracting the number of chromosomes from the required amount in each cell; humans need forty-six chromosomes to function at optimal standards. In most cases, children receive these traits from the inheriting of their parents. These accidental changes can seem minuscule or diminutive to the naked eye, but from a molecular point of reference even the slightest change in genetic make-up can cause a devastating impact on the livelihood of the individual (Campbell, Williamson, & Heyden, 2006). However colorblindness, specifically red-green colorblindness, is sex-linked by the occurrence of dominant and recessive sex-linked alleles. “Sex-linked alleles are those located on one sex chromosome but not the other” (Campbell, Williamson, & Heyden, 2006). The pedigree in figure 1 illustrates how two parents that are neither fully affected can give birth to an affected son. In order for this event to take place, the mother would have had to be a carrier of the disorder.
This is possible because colorblindness is “X-linked recessive,” meaning that the allele for this disorder is only found on the X-chromosome, but the symptoms are hidden due to a dominant allele on another X-chromosome. Since human male only have one X-chromosome, colorblindness is common for this gender. The typical transfer of colorblindness is from a mother carrying the disorder to her son, which will then affect the son. Fortunately not all children of a carrier mother are affected. According to the diagram, the parents only have about a twenty-five percent chance a fully affected son under the given conditions. The unaffected X-chromosome from the mother can combine with either unaffected chromosomes from the father, and the result will be an unaffected offspring (U.S. National Library of Medicine). Within a normally functioning eye, there are three cone cells that correspond with obtaining an individual color – red, green, or blue – designated for the particular cell.
Color blind people are usually missing or subject to a malfunction of at least one of these cone cells. Figures 2 and 3 give diagrams of the human eye to accompany the placement of cone cells. Unlike all genetic disorders, colorblindness can be caused by both genetically and physically changing the cells. By genetics, this disease is gained by inheriting it from a parent (Campbell, Williamson, & Heyden, 2006). During the majority of these genetic instances, a cone cell is just not functioning properly, opposed to not having the cell at all. However this trait can also be obtained after birth with non-parent related causes such as, “aging; eye problems, such as glaucoma, macular degeneration, cataracts, or diabetic retinopathy; injury to the eye; and side effects of some medicines” (WebMD, 2007). These factors make colorblindness different from other types of genetic diseases.
Compared to the ancient origins of other diseases, the history of color blindness is relatively short. “The first case of colorblindness was described in the late 18th century by chemist John Dalton [shown in figure 4], who was himself [color] blind. Dalton is more commonly known for developing the atomic theory, but the first paper he ever wrote described colorblindness in himself and his brother. His research started … on this condition in the scientific community, and today, some call colorblindness Daltonism in honor of his first description” (Boyer, 2012). This new discovery led many notable scientists around the world to dig deeper in their research of the causes, results, and severity of this disorder. As a result of these scientists’ research, a series of symptoms are linked with color vision deficiency. Depending on the severity of the make-up, a varying scale of symptoms may occur. In most cases, the subject is able to see some colors but cannot discern the difference between others, such as red and green; other cases report of people seeing wrong colors, such as mistaking purple for orange and the other way around.
Figure 5 compares the visibility of a typical traffic light from the point of view of a normal human and one diagnosed with red-green colorblindness (Live, 2011). In very extreme events, individuals may not be able to see any color at all, and just see the grayscale. Some animal scientists believe that other species, including canines, are given this disorder of viewing a “black and white world” (A.D.A.M., 2011). Although these symptoms are not necessarily painful, they cause some difficulties. As a child, the ability to learn and read is greatly hindered which causes a great challenge for both the student and parent. As that child grows into adulthood, he or she will face great difficulties when finding a suitable occupation. Jobs such as in the medical, culinary, or graphical fields are nearly impossible for someone with this deformity to be rewarded. However even in the most severe forms of colorblindness, it is rarely ever fatal. Fortunately, testing for this disorder is fairly easy. There are two majorly used tests in the world today.
The most commonly used is the Ishihara Color Vision Test, which is depicted in figure 6. Created by Shinobu Ishihara in 1917, this vision test “consists of a booklet, each page containing a circular pattern (or “plate”) comprising many dots of various colors, brightness and sizes” (Heiting, 2011). Another common form of testing is the Farnsworth-Munsell 100 Hue Test; just as shown in figure 7 the individual has to place color-coated disks in order of increasing or decreasing hue. Together these two tests can pinpoint the ability of the person to discern colors and classify individual shades of those colors. Currently anyone can take these tests at their own leisure by taking them online (Heiting, 2011). Although facile to test for, like most genetic conditions there are little to no true treatments for this disorder. Currently inherited colorblindness is a permanent mutation and there has been little breakthrough of discovering any panacea for this trait. Some slight facilitators are used for minor cases of color vision deficiency, such as wearing anti-glare contact lenses and glasses to help see shades better (WebMD, 2007).
Figure 8 charts the current estimation of people with certain forms of colorblindness. The statistical evidence of this mutation is moderately high throughout the world. “1 in 12 people [in the world] have some sort of color deficiency” (Henderson). Red-green color blindness, the most common type of the disease, “is predominantly found only in men” (Charles). Almost one out of every ten males in the world is diagnosed with Red-Green Colorblindness. In America, Caucasians have the highest chance by percentage of receiving it. Unfortunately the accurate amount of people with this disorder cannot be achieved, because there are some people who do not know that they have the disease. These statisticians have to give a general estimate to account for the unknown that are suffering from colorblindness. Colorblindness is a tough disease to conquer, however it is not unconquerable. In some cases, colorblindness can be seen as an advantage. In the Great War, known today as World War I, soldiers that were confirmed colorblind “were sent on special missions, because their decreased ability to see green led to an increased ability to see through or detect camouflage” (ColorblindSelftest, 2011).
Other American figures have been diagnosed with this disorder and still continue to live a normal life and battle the disease itself. Former President of the United States Bill Clinton is red-green colorblind, but through a strong will to continue on he was granted not only a job, but the job of running the entire country. People such as Clinton do not take the time to complain about their vision, because they are too busy trying to strive to be the best person they can. Acclaimed author Samuel “Mark Twain” Clemens was also diagnosed with Daltonism (Hoffman S. , 2012). He used his vivid imagination and elegant vocabulary to shape the world with his novels and philosophy, instead of complaining about is ailment.
Even “Crayola’s senior crayon maker, Emerson Moser, who molded a record-breaking 1.4 billion crayons in his 37-year career, announced upon his retirement that he was color blind” (Ambrose & Beattie-Moss, 2011). Today, there are organizations that are still active in facilitating with research for this disorder. Shown in figure 9, the National Eye Institute, commonly abbreviated as NEI, “was established by Congress in 1968 to protect and prolong the vision of the American people. NEI research leads to sight-saving treatments, reduces visual impairment and blindness, and improves the quality of life for people of all ages. NEI-supported research has advanced our knowledge of how the visual system functions in health and disease” (National Eye Institute). The NEI and other organizations are very beneficial to the colorblind community, because they help raise awareness for this specific disorder as well as other eye-related disorders. Discovered in the eighteenth century, colorblindness has created a new identity and a new challenge for people to overcome.
“The human eye and brain work together to translate light into color. For the color blind, the eye does not discern colors as others see them. … For some individuals, there is no way to know for certain. Choosing clothes, matching socks and selecting gifts are all very difficult, if not totally frustrating for a person who is color blind” (Hoffman S. , 2012). This genetic disease has shaped the lives of many from birth and others that did not inherit it. The malfunction of just one cell in the eye causes the entire eye to transform its results. It is important not to be discouraged by this disorder, because though this may be a life-changing experience, it is rarely life-threatening. The love that God has on the individual is not less than one that can see properly. In actuality, nobody can truly see clearly by themselves. It takes the dependence on Jesus Christ to allow any human to see what is really in front of them. When Jesus said He was “The Way, The Truth, and The Life…” (John 14:6), He was stating how He is the only clear path to the eternal destiny known as Heaven.