Color blind , also known as lack of color vision , is a decrease in the ability to see colors or color differences. Simple tasks such as choosing ripe fruit, choosing clothes, and reading traffic lights can be more challenging. Color blindness can also make some educational activities more difficult. However, the problem is generally small, and most people find that they can adapt. People with total color blindness (achromatopsia) may also experience a decrease in visual acuity and feel uncomfortable in a bright environment.
The most common color-blind cause is an inherited problem in the development of one or more of three sets of color-sensing cones in the eye. Males are more likely to be color-blind than women, because the genes responsible for the most common color-blind forms are on the X chromosome. Because females have two X chromosomes, the defects in one are usually compensated by another, while men have only one chromosome X. Color blindness can also result from physical or chemical damage to the eyes, optic nerve or part of the brain. Diagnosis is usually with Ishihara color test; However, a number of other testing methods also exist.
There is no cure for color blindness. Diagnosis allows a person's teacher to change their teaching methods to accommodate decreased ability to recognize color. Special lenses can help people with red-green blindness when in sunny conditions. There are also mobile apps that can help people identify colors.
Blindness of red-green is the most common form, followed by blue-yellow and total color blindness. Red-green color blindness affects up to 8% of men and 0.5% of women of North European descent. The ability to see color also decreases in old age. Being color blind can make people unqualified for certain jobs in certain countries. This may include becoming a pilot, train driver and working in the armed forces. The effects of color blindness on artistic ability, however, are controversial. The ability to draw seems unchanged, and a number of famous artists are believed to be color blind.
Video Color blindness
Signs and symptoms
In almost all cases, the color blind man maintains blue-yellow discrimination, and most individual color blindness is an anomalous trichromats rather than a complete dichromate. In practice, this means that they often maintain limited discrimination along the red-green axis, although their ability to separate colors in this dimension is reduced. Color blindness very rarely refers to complete monochromaticism.
Dichromats often confuse red and green items. For example, they may find it difficult to distinguish Braeburn apples from Granny Smith or red from green traffic lights without any other clue - for example, shape or position. Dichromates tend to learn to use textures and guidance shapes and may be able to penetrate camouflages that have been designed to deceive individuals with normal color vision.
The color of traffic lights is confusing for some dichromat because there is no clear distinction between red/yellow traffic lights and sodium streetlights; also, green can be likened to dirty white lights. This is a risk on high-speed corrugated paths where angular gestures can not be used. Rail Rail color light signals use colors that are more easily identifiable: Red is blood red, yellow and green yellow is a bluish color. Most UK street traffic lights are vertically mounted on black rectangles with white borders (forming "observation boards") so that the dichromate can more easily find the position of light inside the rectangle - up, middle or bottom. In the eastern provinces of Canada, horizontally mounted traffic lights are generally distinguished by shape to facilitate identification for those who are color blind. In the United States, this is not done by form but by position, because the red light is always on the left if the light is horizontal, or above if the light is vertical. However, a single flash (eg red to stop, yellow for caution) is still problematic.
Maps Color blindness
Cause
Color blind is usually a genetic disorder that is inherited. It is most commonly inherited from mutations on the X chromosome but the mapping of the human genome has shown there are many causative mutations that can cause color blindness to originate from at least 19 different chromosomes and 56 different genes (as shown online on Mendelian Inheritance Online in Man (OMIM)). The two most common forms of colorblindness inheritance are protanomaly (and, less commonly, protanopia - both commonly known as "protans") and deuteranomaly (or, more rarely, deuteranopia - both commonly referred to as "deutans"). Both "protans" and "deutans" (where deutans are by far the most common) are known as "blind-red-green" which is present in about 8 percent of human men and 0.6 percent of women from northern European ancestors.
Some inherited diseases known to cause color blindness are:
- cone dystrophy
- cone-rod dystrophy
- achromatopsia (rod monochromatism, stationary cone stationary or cone dysfunction syndrome)
- blue cone monochromaticism (blue cone monochromation or blue X-linked akromatopsia)
- Leber's default amaurosis
- retinitis pigmentosa (initially affecting the stems but later can develop into a cone and therefore color blind).
Inherited blind colors can be congenital (from birth), or can be started in childhood or adulthood. Depending on the mutation, it can be stationary, meaning it remains the same throughout a person's lifetime, or progressively. Because progressive phenotypes involve retina deterioration and other eye parts, certain forms of color blindness can develop into legal blindness, ie sharpness 6/60 (20/200) or worse, and often leave a person with complete blindness..
Color blind is always associated with the cone photoreceptors in the retina, as the cones are able to detect the frequency of light.
About 8 percent of men, and 0.6 percent of women, are red-green blind in some way or another, whether it's a color, color combination, or other mutation. The reason men are at greater risk inheriting an associated mutation X is that men have only one X chromosome (XY, with Y chromosome carrying genes completely different from the X chromosome), and women have two (XX); if a woman inherits a normal X chromosome other than a carrying mutation, she will not display the mutation. Men do not have a second X chromosome to rule out a chromosome carrying a mutation. If the 8% variant of the given gene is damaged, the probability of one damaged copy is 8%, but the probability that two copies of both are damaged is 0.08 ÃÆ'â € 0,08 = 0,0064, or only 0.64%.
Other causes
Other causes of color blindness include brain or retinal damage caused by shaken baby syndrome, accidents and other traumas that produce brain swelling in the occipital lobe, and damage to the retina caused by exposure to ultraviolet (10-300 nm) rays. Damage often appears on its own in the future.
Color blindness can also appear in the spectrum of degenerative diseases in the eye, such as age-related macular degeneration, and as part of retinal damage caused by diabetes. Other factors that may affect color blind include vitamin A deficiency.
Some subtle forms of color blindness may be associated with chronic-triggered encephalopathy (CSE), caused by prolonged exposure to steam solvents.
Blindness of red-green can be caused by ethambutol, a drug used in the treatment of tuberculosis.
Type
Based on clinical appearance, color blindness can be described as total or partial. Total color blindness is much more common than partial color blindness. There are two main types of color blindness: those who have difficulty differentiating between red and green, and who have difficulty distinguishing between blue and yellow.
Immunofluorescent imaging is a way of determining red-green color encoding. Conventional color coding is difficult for individuals with red-green blindness (protanopia or deuteranopia) to discriminate. Replacing red with magenta or green with turquoise increases visibility for the individual.
Different types of inherited color blindness result from partial or complete loss of function from one or more different cone systems. When a cone system is compromised, results are criticized. The form of human color blindness most often results from problems with long or long wavelength sensitive cone systems, and involves difficulties in distinguishing red, yellow, and green from each other. They are collectively referred to as "red-green blind", although the term is oversimplified and somewhat misleading. Other forms of color blind are much less frequent. They include the problem of distinguishing blues from green and yellow from red/pink, and the rarest form of all, complete color blindness or monochromatic , in which one can not distinguish any color from gray , as in black-and movies or white photos.
Protanope, deuteranopes, and tritanopes are dichromates; that is, they can match any color they see with some mixture of only two primary colors (whereas humans are usually trichromat and require three primary colors). These people usually know they have color vision problems and can affect their lives every day. Two percent of the male population shows severe difficulties distinguishing between red, orange, yellow, and green. A certain pair of colors, which look very different from the normal viewer, looks like the same color (or different color shades) for the dichromate. The term protanopia, deuteranopia, and tritanopia comes from Greek and literally means "inability to see ( anopia ) with the first ( prot - ), the second ( deuter - ), or the third ( trit - ) [cone] ", respectively.
Trichromation anomaly is the most serious type of color deficiency. People with protanomaly, deuteranomaly, or tritanomaly are trichromats, but the colors they make are different from the normal ones. They are called trichromats anomalies. To match the given spectral yellow light, the protanomal observer requires more red light in the red/green mix than the normal observer, and deuteranomalous observers require more green color. From a practical point of view though, many protanomalous and deuteranomalous people have little difficulty carrying out tasks that require normal color vision. Some may not even realize that their color perception is different from normal.
Protanomaly and deuteranomaly can be diagnosed by means of a device called anomaloscope, which mixes red and spectral green in variable proportions, for comparison with the fixed yellow spectrum. If this is done in front of many male listeners, since the proportion of red increases from a low value, firstly a small percentage of viewers will declare a match, while most will see the mixture of light as greenish; this is a deuteranomalous observer. Furthermore, as more red color is added, the majority will say that the match has been reached. Finally, as more red is added, remaining, protanomal, the observer will declare a match at the point where the normal observer will see the mixed light as definitely reddish.
Blind red-green
Protanopia, deuteranopia, protanomali, and deuteranomali generally inherit red-green blind forms that affect the vast majority of the human population. Those affected have difficulty distinguishing between red and green due to the absence or mutation of the red or green retinal photoreceptors. It's sex-related: genetic red-green blindness affects males much more often than females, because the gene for red and green receptors lies on the X chromosome, where men have only one and women have two. Women (46, XX) are red-green blind only if both their X chromosomes are damaged by the same deficiency, while males (46, XY) are color-blind if their single X chromosome is damaged.
Genes for green-red blindness are transmitted from color-blind men to all of their daughters who are heterozygous carriers and are usually unaffected. In turn, a career woman has a fifty percent chance of continuing the X chromosome region that has mutated into each of her male descendants. Infected boys will not inherit the nature of it, because they receive their Y chromosome and not the damaged X chromosome. If an affected man has a child with a carrier or a color-blind woman, their daughter may be color blind by inheriting the affected X chromosome from each parent.
Since one X chromosome is randomly active in each cell during a woman's development, deuteranomal heterozygotes (ie deuteranomaly female carriers) are potential tetrachromates, as they will have normal wavelength (red) receptors, normal medium-wave recipe (green), mid-wave receptors (deuteranomalous) abnormal and normal (blue) autosomal shortwave receptors in their retina. The same is true for protanomaly carriers (which have two types of shortwave receptors, normal mid-wave receptors, and normal autosomal short-wave receptors in their retinas). If, by chance, a heterozygous woman for both protanomaly and deuteranomaly she can be pentachromatic. This situation may arise if, for example, it inherits the X chromosome with abnormal longwave genes (but normal mid-wavelength genes) from its mother who is a protanomal carrier, and another X chromosome of the deuteranomalous father. Such women will have normal and abnormal long-wave receptors, normal and abnormal mid-level receptors, and normal autosomal short-wave receptors - 5 different color receptor types. The extent to which women are carriers of either protanomaly or deuteranomaly are proven to be tetrachromatic and require a mixture of four spectral lights to match arbitrarily varying light. In many cases it is almost subtle, but in the minority tetrachromacy is felt. However, Jameson et al. has shown that with proper and sensitive equipment, all female carriers of red-green blindness (ie heterozygous protanomaly, or deuteranomal heterozygotes) are tetrachromates to a greater or lesser extent.
Since deuteranomaly is by far the most common form of red-green blindness among men of northwestern descent (with an 8% incidence), the carrier frequency (and potential deuteranomalous tetrachromacy) among females from the genetic stock is 14.7% = [92% ÃÆ'â € "8%] ÃÆ'â €" 2).
- Protanopia (1% male): Lack of a red cone for long wavelength retinal cones, those with this condition can not distinguish the color in the green-yellow-red part of the spectrum. They have a neutral point at wavelengths like-cyan about 492 nm (see spectral colors for comparison) - that is, they can not distinguish this wavelength light from white. For the protanope, the brightness of red, orange, and yellow is much less than normal. This dimming can be so conspicuous that red can be mistaken with black or dark gray, and red traffic lights may appear to be out. They may learn to distinguish red from yellow mainly based on brightness or brightness, not on clear color differences. Violet, lavender, and purple can not be distinguished from the various gradations of blue because their reddish components are so dim so invisible. For example, pink flowers, which reflect red and blue light, may appear blue to protanope. Few people are found who have one normal eye and one eye protanopi. These unilateral dichromats report that with only their open protanopic eyes, they see shorter wavelengths from the neutral point as blue and longer than yellow. This is a rare form of color blindness.
- Deuteranopia (1% of men): The lack of a green cone for the wavelength cones, those affected again can not distinguish between the colors in the green-yellow-red part of the spectrum. Their neutral point is at a slightly longer wavelength, 498 nm, a more greenish color than cyan. A deuteranope suffers the same color discrimination problem as the protanope, but without the abnormal dimming. The purple color is not considered as opposed to the spectral color; all these appear the same. This form of color blindness is also known as Daltonism after John Dalton (his diagnosis was confirmed as deuteranopia in 1995, some 150 years after his death, by DNA analysis of his preserved eye). Equivalent terms for Daltonisme in Roman like daltonismo (Spanish, Portuguese and Italian), daltonism (France), daltonism (Romanian) is still used for describes color blindness in a broad sense or deuteranopia in a more limited sense. Deuteranopic unilateral dichromats report that only with open deuteranopic eyes, they see shorter wavelengths than neutral points as blue and longer than yellow.
- Protanomaly (1% male, 0.01% female): Has a mutation form of long-length pigment (red), whose peak sensitivity at wavelength is shorter than the retina normal, protanomal individuals are less sensitive to red light than normal. This means that they are less able to distinguish colors, and they do not see mixed lights having the same color as regular observers. They also suffer from the darkening of the red end of the spectrum. This causes red to reduce the intensity to the point where they can be mistaken for black. Protanomali is a fairly rare form of color blindness, accounting for about 1% of the male population. Both protanomali and deuteranomaly are carried on the X chromosome.
- Deuteranomaly (most common - 6% male, 0.4% female): This individual has a form of wavelength (green) pigment mutation. The medium wavelength pigment shifts toward the red end of the spectrum resulting in a reduction of sensitivity to the green area of ​​the spectrum. Unlike protanomaly, the color intensity does not change. Deuteranomal people are considered "weak green". For example, at night, dark green cars look black to deuteranomalous people. Similar to protanomates, deuteranomates are evident in distinguishing small differences in color in the areas of the red, orange, yellow, green spectrum. They made a mistake in naming the colors in this region because the colors seemed to shift slightly toward the green. One very important difference between the deuteranomalous individual and the protanomal individual is the deuteranomal individual who does not experience a "brightness" problem.
Blue-yellow blindness
Those with tritanopia and tritanomaly have difficulty distinguishing between bluish and greenish colors, as well as yellowish and reddish colors.
Color blindness involving the inactivation of short-wavelength sensitive cone systems (the peak of the absorption spectrum in purple blues) is called tritanopia or, blue-yellow blindness. The tritanope neutral point occurs near the yellowish 570 nm; green is felt at shorter and red wavelengths at longer wavelengths. The wavelength-sensitive cone mutation is called tritanomaly . Tritanopia is spread evenly among men and women. Jeremy H. Nathans (with Howard Hughes Medical Institute) suggests that the gene encoding the blue receptor lies on chromosome 7, which is shared equally by men and women. Therefore, it is not sex related. This gene does not have a neighbor whose DNA sequence is similar. Blue blind is caused by simple mutations in this gene.
- Tritanopia : Less than 1% of men and women: Lack of short wavelength cones, those affected see short-wavelength (blue, indigo and violet spectral) dimmed, some of these colors even black. Yellow is indistinguishable from pink, and purple is considered a variety of red shades. This form of color blindness is not related to gender.
- Tritanomaly (equally rare for both men and women [0.01% for both]): Has a short-length (blue) pigment mutation form. Short wavelength pigments shift toward the green area of ​​the spectrum. This is the rarest form of anomalous color blindness blindness. In contrast to the color deficiency of other anomalous trichromations, these mutations for color blindness are performed on chromosome 7. Therefore, it is equally common in both male and female populations. The OMIM gene code for this mutation is 304000 "Color Blur, Partial Tritanomaly".
Total color blind
Total color blindness is defined as the inability to see color. Although this term may refer to acquired disorders such as cerebral akebomatopsia, also known as color agnosia, this usually refers to congenital color vision impairment (ie more frequent stem monochromation and less rare monochromatic cones).
In cerebral achromatopsia, one can not see color even though the eye is able to distinguish it. Some sources do not regard this as true color blindness, because failure is perception, not vision. They are a form of visual agnosia.
Monochromation is a condition of having only one channel to convey information about color. Monochromate has an inability to distinguish any color and only senses variations in brightness. This happens in two main forms:
- Rod monochromation, often called achromatopsia , in which the retina contains no conical cells, so in addition to the absence of color discrimination, sight in light with normal intensity is difficult. Although usually rare, achromatopsia is very common on the island of Pingelap, part of the state of Pohnpei, Federated States of Micronesia, where it is called maskun : about 10% of the population there, and 30% are unaffected operators. The island was destroyed by a storm in the 18th century (an example of a genetic bottleneck) and one of the few surviving men carrying the gene for achromatopsia. The population grew to several thousand before foreign troops introduced the disease to the island in the 1940s.
- Monochromatic cones are a condition of having rods and cones, but only one type of cone. Monochromate cones can have good pattern vision at normal daytime levels, but will not be able to discriminate colors. Monochromatic blue cone (X chromosome) is caused by the lack of functionality of L and M cone (red and green). It is encoded in the same place as the red-green blindness on the X chromosome. The peak spectral sensitivity is in the visible blue region of the spectrum (near 440Ã, nm). People with this condition generally show nystagmus ("shaking eyes"), photophobia (light sensitivity), reduced visual acuity, and myopia (farsightedness). Visual acuity usually falls into the 20/50 to 20/400 range.
Mechanism
A typical human retina contains two types of light cells: stem cells (active in low light) and cone cells (active in normal daylight). Typically, there are three types of conical cells, each containing a different pigment, which is activated when the pigment absorbs light. Spectral sensitivity of different cones; which are most sensitive to short wavelengths, one to medium wavelengths, and third to medium wavelengths in the visible spectrum, with their peak sensitivity in the blue, green, and yellow-green spectrum regions, respectively. The absorption spectra of the three systems overlap, and are combined to cover the visible spectrum. These receptors are known as short wavelength cones (S), medium (M), and long (L), but are also often referred to as blue, green, and red cones, although this terminology is not accurate.
Each receptor is responsive to different wavelengths. For example, long wavelength "red" receptors have peak sensitivity in yellow-green, some way from the red end (longest wavelength) of the visible spectrum. Normal color vision sensitivity actually depends on the overlap between the absorption range of the three systems: different colors are recognized when different types of cones are stimulated to different degrees. The red light, for example, stimulates the wavelength cone far more than the others, and reduces the wavelength causing the other two cone systems to become increasingly stimulated, causing a gradual change of color.
Many of the genes involved in color vision are on the X chromosome, making color blinds much more common in men than in women because men have only one X chromosome, while women have two X chromosomes. Because this is an X-linked nature, it is estimated that 2-3 % of women have a 4th color cone and can be considered tetromromate. One such woman has been reported as a true or functional tetrachromat, because she can distinguish colors not shared by most others.
Diagnosis
The Ishihara color test, which consists of a series of colored spots, is the most commonly used test to diagnose red-green deficiency. The figure (usually one or more Arabic numerals) is embedded in the image as a number of spots in slightly different colors, and can be seen with normal color vision, but not with certain color defects. The full set of tests has various color combinations of images/backgrounds, and allows the diagnosis of certain visual defects that are present. Anomaloscope, described above, is also used in diagnosing anomaly seizure tricks.
Position yourself about 75 cm from your monitor so that the color test image you see is eye level, read the image description and see what you can see !! It is not necessary in all cases to use the whole set of images. In large-scale testing, the test can be simplified into six tests; test, one of 2 or 3 tests, one of 4, 5, 6, or 7 tests, one of 8 or 9 tests, one of 10, 11, 12, or 13 tests and one test 14 or 15.
Since the Ishihara color test contains only numbers, it may not be useful in diagnosing children, who have not learned to use numbers. For the sake of identifying these issues early on in life, alternative color vision tests are developed using only symbols (square, circle, car).
In addition to the Ishihara color test, the US Navy and the US Army also allow testing with the Farnsworth Lantern Test. This test allows 30% of individuals who lack the color, the drawback is not too heavy, to pass.
Another test used by doctors to measure color discrimination is the Farnsworth-Munsell 100 test. The patient is asked to arrange a set of colored caps or chips to form a gradual color transition between two cap anchors.
The HRR color test (developed by Hardy, Rand, and Rittler) is a red-green test that, unlike Ishihara, also has plates to detect tritan flaws.
Most clinical trials are designed to be fast, simple, and effective in identifying the broad categories of color blindness. In an academic study of color blindness, on the other hand, there is a greater interest in developing flexible tests to collect comprehensive data sets, identify copunctal dots, and measure real differences.
Management
Generally there is no treatment to cure the lack of color. "The American Optometric Association reported contact lenses on one eye can improve the ability to distinguish between colors, although nothing can make you really see the color that is lacking."
Lens
Opticians can provide colored eyeglass lenses or red contact lenses to wear on non-dominant eyes, but although this may increase the discrimination of some colors, this can make other colors more difficult to distinguish. A 1981 review of various studies to evaluate the effects of chromium-X contact lenses concluded that, while the lens allows the wearer to achieve better scores on certain color vision tests, it does not correct the color vision in the natural environment. The case history using X-Chrom lens for reported bar monochromate and X-Chrom manual is online.
Lenses that filter certain wavelengths of light can allow people with cone anomalies, but not dichotomies, to see better color separation, especially those with classic "red/green" blindness. They work by spreading wavelengths that greatly stimulate red and green cones in adults or protanomalous, increasing the difference between two cone signals. In 2013, sunglasses that show color wavelengths are commercially available.
Apps
Many apps for iPhone and iPad have been developed to help color blind people to see colors in a better way. Many apps launch a kind of color blind vision simulation to make people who see normal understand how color curtains look at the world. Others allow camera image correction with special "daltonizer" algorithms.
The GNOME desktop environment provides dark color accessibility using gnome-mag and libcolorblind software. Using the gnome applet, users can enable and disable color filters, selecting from a set of possible color transformations that will replace the colors to split them. This software allows, for example, the color blind to see the numbers in the Ishihara test.
Epidemiology
Color blind affects large numbers of individuals, with protanopia and deuteranopia being the most common type. In individuals with northern European ancestors, as many as 8 percent of men and 0.4 percent of women have congenital color deficiency.
The number of affected varies between groups. An isolated community with restricted gene pools sometimes produces high proportions of color blindness, including the less common types. Examples include the Finnish, Hungarian, and Scottish islands. In the United States, about 7 percent of the male population - or about 10.5 million men - and 0.4 percent of the female population can not distinguish red from green, or see red and green differently than others do (Howard Hughes Medical Institute, 2006). More than 95 percent of all variations in human color vision involve red and green receptors in the eyes of men. It is rare for men or women to be "blind" with the blue end of the spectrum.
History
The first scientific paper on the subject of color blindness, The extraordinary facts relating to color vision, was published by the English chemist John Dalton in 1798 after the realization of his own color blindness. Because of Dalton's work, the general condition has been called daltonism, although in English the term is now used only for deuteranopia.
Society and culture
Design implications
The color code presents a special problem for those who are lacking color because it is often difficult or impossible for them to see.
Good graphic design avoids using color codes or using color contrast only to express information; this not only helps the color blind, but also helps understanding by people who are usually seen by giving them some reinforcing clues.
Designers need to consider that color blindness is very sensitive to material differences. For example, a red-green blind person who is unable to distinguish colors on a map printed on paper may not experience such difficulty when looking at a map on a computer or television screen. In addition, some color blind people find it easier to distinguish color problems on artificial materials, such as plastic or acrylic paint, than natural materials, such as paper or wood. Thirdly, for some color blind people, color can only be distinguished if there is enough "mass" color: thin lines may appear black, while thick lines of the same color can be considered to have color.
Designers should also note that the blue-red and yellow-blue color combinations are generally safe. So instead of the well-known "red means bad and green means good" systems, using this combination can lead to a much higher ability to use color coding effectively. This will still cause problems for those who are monochromatic color blind, but that is still something worth considering.
When the need to process visual information as quickly as possible arises, for example in an emergency situation, the visual system can operate only in shades of gray, with additional information load in adding the dropped color. This is an important possibility to consider when designing, for example, emergency hand brake or emergency phone.
Jobs
Color blindness may make it difficult or impossible for a person to engage in a particular job. People with color blindness may be legally or practically prohibited from work where color perception is an important part of the work (eg, paint color blending), or where color perception is important for safety (eg, operational vehicle in response to color-coded signal). The principle of safety comes from the 1875 Lagerlunda train wreck in Sweden. After the accident, Professor Alarik Frithiof Holmgren, a physiologist, investigated and concluded that color blind engineers (who had died) had caused the accident. Professor Holmgren then made the first test using different color skeins to exclude people from work in the transportation industry on the basis of color blindness. However, there are claims that there is no solid evidence that color deficiency does cause collisions, or that it may not be the only cause.
Vision color is important for the job using a telephone cable or computer network, because individual cables inside the cables are color-coded using green, orange, brown, blue and white. The electronic cables, transformers, resistors, and capacitors are color-coded as well, using black, brown, red, orange, yellow, green, blue, purple, gray, white, silver, gold.
Driving
Some countries refuse to grant driver licenses to individuals with color blindness. In Romania, there are ongoing campaigns to remove legal restrictions that prohibit blind people from obtaining driver licenses.
The usual justification for such restrictions is that motorists must be able to recognize color-coded signals, such as traffic lights or warning lights.
Pioneer aircraft
While many aspects of flight depend on color codes, only a few of them are important enough to be interfered with by some kind of lighter color blindness. Some examples include color-plane signals that have lost radio communications, color-coded glide-path indications on runways, and the like. Some jurisdictions limit the publishing of the experimental credentials to people suffering from color blindness for this reason. Limitations may be partial, allowing color blind people to obtain certification but with restrictions, or totals, where people who are color blind are not allowed to obtain a piloting identity at all.
In the United States, the Federal Aviation Administration requires pilots to be tested for normal color vision as part of their medical clearance to obtain the necessary medical certificates, a prerequisite for obtaining pilot certification. If testing indicates color blindness, applicants may issue licenses with restrictions, such as no night flights and do not fly with color signals - such restrictions effectively prevent pilots from holding certain flying jobs, such as aircraft pilots, Although commercial certification testing is still possible, and there are some flying jobs that do not require an evening flight and thus are still available to those with color-blind restrictions (eg, aviation aviation). The government allows several types of tests, including standard medical tests (eg iHihara, Dvorine, etc.) and special tests that are oriented specifically on aviation needs. If the applicant fails the standard test, they will accept a restriction on their medical certificate stating: "Not applicable for night flight or with color signal control". They can apply to the FAA to take a special test, administered by the FAA. Typically, this test is a "color vision lamp test rifle". For this test the FAA inspector will meet the pilot at the airport with a control tower operation. Light signal color weapons will shine on the pilot from the tower, and they must identify the colors. If they pass they may be issued a waiver, stating that a color vision test is no longer needed during a medical examination. They will then receive a new medical certificate with the restrictions removed. It was once a Demonstration Demonstration Statement (SODA), but SODA was dropped, and changed to a simple lettering in the early 2000s.
Research published in 2009 conducted by the Center for Applied Vision Research City University of London, sponsored by the British Civil Aviation Authority and the US Federal Aviation Administration, has established more accurate assessments of color deficiencies in 'red-green and yellow- a blue color range that could lead to a 35% reduction in the number of potential pilots who fail to meet the minimum medical threshold.
Art
The inability to distinguish colors does not necessarily preclude the ability to become a famous artist. 20th century expressionist painter Clifton Pugh, a three-time winner of the Australian Archibald Award, about biographies, genetic inheritance and other reasons has been identified as protanope. 19th Century French artist Charles MÃÆ'Ã… © ryon became successful by concentrating on etching rather than painting after he was diagnosed with a red-green deficiency.
Color blindness
Brazil
The Brazilian Court ruled that people with color blindness were protected by the Inter-American Convention on the Elimination of All Forms of Discrimination against Persons with Disabilities.
In the trial, it was decided that carriers of color blindness had access to a wider knowledge, or the full enjoyment of their human condition.
United States
In the United States, under federal anti-discrimination laws such as the Americans with Disabilities Act, the lack of color vision has not been found as a flaw that triggers protection from discrimination in the workplace.
The famous traffic light at Tipperary Hill in Syracuse, New York, was reversed because of the sentiments of the Irish American community, but has been criticized for its potential dangers to color blind people.
Research
Some tentative evidence found that color blindness was better at penetrating certain color camouflage. Such findings may provide an evolutionary reason for the high rate of green-red blindness. There is also research showing that people with some type of color blindness can distinguish colors that people with normal color vision can not tell the difference. In World War II, a color-blind observer was used to penetrate camouflage.
In September 2009, the journal Nature has reported that researchers at the University of Washington and the University of Florida were able to provide trichromatic vision to squirrel monkeys, who typically have only dichromatic vision, using gene therapy.
- Blind color in Curlie (based on DMOZ)
- "Color Science Glossary."
Source of the article : Wikipedia
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