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Color Blind Test

The Online Color Blind Test is developed to measure whether a person is color blind or not. You can also learn more information about Color Blindness.

What is Color Blindness?

Color Blindness is not a kind of blindness but a deficiency in the way one sees color. It leads to difficulty in distinguishing certain colors like red and green or blue and yellow.

Using the term "Color Blindness" could be misleading because most Color Blind people can see colors, but their color perception is limited to an extent, washed out, and imprecise. The most common kind of color vision deficiency tends to cause an inaccurate perception of the colors red and green, which makes it easy to confuse them.

Causes of Color Blindness:

Color blindness is caused when light-sensitive cells in the retina do not respond suitably to variations in light wavelengths that help people see various colors. The retina consists of two types of cells that detect light, rods, and cones.

There are approximately 100 million rods in the human retina, and they are more sensitive to light but are unable to perceive color. Rods can detect only light and dark; they are susceptible to low levels of light.

There are close to 6 to 7 million cones in the human retina responsible for color vision. On the other hand, detect color and are intensely situated near the center of one's vision. These photoreceptors exist in the central zone of the retina, called the macula.

Fovea, the macula's center, is only 0.3 mm in diameter and consists of the highest concentration of cones in the retina, making it responsible for acute color vision.

Color blindness can arise when one or more of the color cone cells are absent, fail to work, or detect a different color than the usual. Severe color blindness occurs when all of the three cone cells are absent. Mild color blindness occurs when all three cone cells are present, but one cone cell does not quite work right, detecting a different color than normal.

Hence, deficiencies in certain cones or the absence of these cones are often related to color blindness.

Color blindness can also occur due to aging, which causes damage to retinal cells over time. An injury or damage to the brain areas where vision is processed can also cause color vision deficiencies.

Certain medications, like antipsychotic medications, can cause changes in color vision. The antibiotic which treats tuberculosis may lead to optic nerve problems and difficulty in seeing some colors. Besides, toxic chemicals such as styrene, present in some plastics, is linked to the loss of ability to see color.

Heredity linked to Red-Green Color Blindness:

Both parents contribute to chromosomes that determine the sex of the baby.

Mothers have an X-X pairing of chromosomes, while fathers have an X-Y pairing. When X chromosomes pairs with another X, the baby is a female. And when the X chromosomes pairs with the Y, the baby is male.

A common X-linked recessive gene is attributed to causing red-green color blindness. Males have only one X chromosome, and females have two; if a female inherits a normal X chromosome in addition to the chromosome that carries the mutation, the mutation is not displayed. As men lack a second X chromosome to override the chromosome that carries the mutation, males are believed to be at a greater risk of inheriting an X-linked mutation.

Fathers with inherited red-green color blindness pass on the X-linked gene to their daughters; a son cannot receive X-linked genetic material from his father.

If a daughter inherits the color-deficient gene from her father, she will only be a carrier unless her mother also happens to have the color-deficient gene. If a daughter inherits the X-linked trait from both her parents, she will be a carrier and color blind.

Besides differences in the genetic makeup system, color vision defects or loss can also be caused by:

Parkinson's disease - Parkinson's disease is a neurodegenerative disorder caused by a loss of nerve cells in a part of the brain, which leads to a reduction in a chemical called dopamine in the brain. Dopamine plays an important role in regulating movement in the body.

A reduction in dopamine is attributed to many of the symptoms related to Parkinson's disease. PD causes a loss of retinal cells in the eye that rely on dopamine in processing and perceiving color. Light-sensitive nerve cells in the retina where the vision is processed might get damaged and cannot function properly. Parkinson's may also reduce the ability to sense individual colors or make them appear in a duller form.

Cataracts cause clouding of the eye's lens to wash out the color vision, making it much less bright. Color vibrancy is severely reduced with cataracts. Hence the common misconception prevails that it is a form of color blindness.

However, along with vibrancy, clarity is also reduced along with symptoms of, etc. Cataracts disable correct vision by obscuring incoming light waves rather than having a defect in the eye structure or a genetic mutation.

Tiagabine, an antiepileptic drug to control partial seizures in epilepsy, it has shown to reduce color vision in about 41 percent of those consuming the drug. However, effects do not appear to be permanent.

Leber's hereditary optic neuropathy is an inherited form of vision loss. For unknown reasons, males are affected much more often than females. Particularly prevalent among males, it can even affect carriers who don't have other symptoms but have a persistent color blindness degree.

Red-green color vision defects are noted to have this condition. Blurring and clouding of vision are the primary symptoms of LHON. These vision problems may occur in one eye or both eyes; if vision loss starts in one eye, the other eye is consequently affected within several weeks or months. Over time, both eyes' vision becomes worse, accompanied by a severe loss of sharpness and color vision.

Color Blindness Symptoms and Signs:

The most widespread symptom of color blindness is a vision change. It may get difficult to distinguish between traffic lights. Colors may seem less bright than before or usual. Different shades of color may all end up looking the same.

The symptoms of color blindness can vary from a scale of mild to severe. Many people face such mild symptoms that they are unaware of the color deficiency they are suffering from. Parents may only notice a color deficiency issue with a child when they are learning colors.

The symptoms include:

  • Trouble seeing and distinguishing colors and its brightness.
  • Inability to differentiate between similar shades and hues. This occurs the most with red and green, or blue and yellow.
  • Lack of the ability to see shades or tones of the same color.
  • Color blindness affects the sharpness of vision only if it's very severe. The incapability to see any color at all and see everything only in shades of gray is called achromatopsia.

Types of Color Blindness:

The most common kinds of color blindness are usually inherited. They occur as the result of defects within the genes that help make the photopigments found in cones. Some defects tend to alter the photo pigment's sensitivity to color. Other defects can result in the absolute loss of a photopigment.

Depending on the type of defect one has and the cone that gets affected, problems tend to occur with green, red, or blue color vision.

Red-Green Color Blindness:

The most regular types of hereditary color blindness occur due to the loss or limited function of a cone, and the red cone is also known as protan or green cone, also known as deutran photopigments. This kind of color blindness is referred to as red-green color blindness.

Red-green color deficiency is the most common kind of color blindness.

  • Protanomaly - In males with protanomaly, red, orange, and yellow appear greener, and the colors are not as bright. This is a mild condition and doesn't usually interfere with one's day to day life. Protanomaly is an X chromosome-linked disorder that is estimated to affect 1% of males. They suffer from a darkening of the red end of the spectrum, which causes reds to reduce in their intensity to the point where they could be mistaken for black. Protanomaly is quite a rare form of color blindness, making up about 0.01% of the female population.

  • Protanopia - Males with protanopia have no working red cone cells, making red appear as black. Most shades of orange, yellow, and green appear as yellow. Protanopia is carried out on the X chromosome, affecting 1% of the male population. In this condition, the brightness of red, orange, and yellow is highly reduced compared to normal. This dimming can be prominent enough to confuse the color red with black or dark gray. They may learn to differentiate reds from yellows based on their brightness or lightness and not on any hue difference.

  • Deuteranomaly - In deuteranomaly, the green cone photopigment is abnormal; they are considered green weak as hues appear to be shifted towards green. Yellow and green appear in redder hues, and it is difficult for them to tell violet from blue. This is a mild condition and is the most common form of color blindness carried out by an X chromosome, affecting 5 percent of males.

  • Deuteranopia - The green cone cells have ceased working, and they tend to see reds as brownish-yellow and greens as beige. Deuteranopia is considered to be an X-linked disorder affecting about 1% of males.

Blue-Yellow Color Blindness:

The blue-yellow congenital abnormality is rarer than a red-green congenital abnormality. They have difficulty distinguishing between blue and green hues, as well as yellow and red hues.

  • Tritanomaly - People with tritanomaly have a functionally restricted degree of blue cone cells. Blue seems greener, and it can be difficult to tell yellow and red from pink and purple colors are seen as various shades of red. Tritanomaly is exceptionally rare. Males and females are equally affected and are not particularly sex-linked.

  • Tritanopia - Also known as blue-yellow color blindness, are in short of blue cone cells. Blue appears to be green, and yellow seems to be violet or light grey. Tritanopia is an extremely rare disorder that affects both males and females equally.

Complete Color Blindness:

It is the inability to see color; people with complete color blindness (monochromacy) don't experience color. The two types of monochromacy are:

  • Cone monochromacy - This rare kind of color blindness results from two of the three cone cells not working. There exists red cone monochromacy, green cone monochromacy, and blue cone monochromacy. People with cone monochromacy have trouble distinguishing between colors because the brain compares the signals from different cones to see color. When only one type of cone works, this comparison becomes impossible. People suffering from blue cone monochromacy may also have reduced visual clarity, short-sightedness, accompanied by uncontrollable eye movements.

  • Rod monochromacy or achromatopsia - This is rare and is the most severe form of color blindness. It is present since birth. None of the cone cells function or have working photopigments. They lack all cone vision, seeing the world in black, white, and gray. And as rods only respond to dim light, people with rod monochromacy tend to feel very uncomfortable in bright environments.

How is Color Blindness Tested?

Many tests measure color vision defects, but the most common is the Ishihara Plate test. This test's for red/green color blindness. This test is most likely to be used for routine color vision screening in schools or medicals.

It contains 38 plates of circles which are created by random colored dots in two or more colors. The plates will be placed in front of the person, and they will be asked what number can be seen on the plate.

Some of the plates contain information which people with normal color vision can see while on the other hand, other plates contain information that only people with color blindness have access to.

If the person makes a certain amount of errors, they are diagnosed with color blindness. Special Plate tests have been made to diagnose young children who aren't old enough to identify numbers.

For a more detailed examination of color blindness and a person's ability to precisely perceive colors, a quantitative color blind test is required — the most popular test being the Farnsworth-Munsell 100 Hue Test, identifying and quantifying color vision issues.

This test comprises of four trays which contain various small disks of varying hues. Each tray has a colored reference disk on one end. The person being tested ought to arrange the other disks within the tray to create a range of colors that depict the hue's gradual change.

For the most accurate results, the test should be administered in a viewing booth with natural daylight. It is also advised for the colored disks to be replaced at least every two years to prevent it from loss of color saturation that could affect the test's outcome.

Each colored disk is given a number at the bottom, which enables scoring. The closer the match is between the test sequence and the correct sequence, the higher the accuracy of detecting the person's color perception.

In this manner, the 100 Hue Test detects if the person being tested is colorblind and also helps determine the severity and type of their color blindness.

Color Blindness Treatment and Strategies:

Currently, there is no known cure for achromatopsia, a genetic disorder in which a child is born with nonfunctioning cones. Research on gene therapy is still in progress and might lead to clinical treatments in the future. When tested on animals, gene therapy has shown potential in restoring some cone function in the retina.

Children should be checked for the need for glasses. Prescribing glasses to correct far-sightedness, near-sightedness will improve the vision but do not restore normal levels of vision. Red-colored lenses help in reducing the sensitivity to light and hence enhance visual functions.

A newer device known as an eyeborg helps people with color blindness to perceive color through sound waves. A cyborg antenna is a device implanted in a human skull.

The antenna consists of a wireless camera on one end of it and a wireless sound vibration implant on the other end, allowing wireless communication and transmission of images, sound, or video.

In the beginning, the person might get frequent headaches because of all the sounds they are exposed to, but they adapt to it in five weeks. The antenna uses audio vibration in the skull to report information. This includes color.

Lenses and Glasses for Color Blindness:

Optometrists supply colored specks lenses or a single red-tint contact lens to improve discrimination of some colors. However, it can make other colors more difficult to differentiate.

Most people consist of three types of color-sensing cones in their eyes: red, green, and blue. The wavelengths of light that are absorbed by these cones include overlapping regions. Color-blindness is often a result of a malfunctioning cone, which causes wavelengths to overlap even more, consequently leading to poor color discrimination.

Colorblind glasses have exclusively tinted lenses that help a person with color blindness see colors more accurately; it allows them to see with accuracy and exposes them to a greater spectrum of colors.

The colorblind glasses make use of a filter to cut out the overlapping wavelengths, which allow for a clearer differentiation between colors, especially red and green.

Colorblind glasses also have very realistic applications, such as assisting a colorblind person in selecting clothes whilst matching patterns and colors. It also promotes growth in one's career as some professions, such as graphic designing and work profiles that require handling various electrical wiring colors, depends on accurate color perception.

Living with Color Blindness:

It's common to think that the biggest issue color blind people face is gauging the traffic lights; some states don't allow them to get a driver's license if they are color blind. But it doesn't stop at the traffic lights, and color blind people have difficulty with simple tasks that require one to differentiate between colors; matching clothes is one among them.

They can't really tell if they've been sunburnt or if the meat is cooked right, flowers and fruits are not easily spotted, and they can't tell if it's ripe or not. Colored maps and graphics can be tough to decipher.

Choosing a career is also challenging for the colorblind people as bad color vision could pose risks and security problems in jobs that require color differentiation like an electrical engineer, train driver, airline pilot, firefighter, etc. And for these jobs passing a color blindness test is mandatory to qualify.

Simple tips that help navigate Color Blindness:

Check out the most common color blindness tips that will help you to change some basic habits.

  • Choosing Clothes - When shopping, using an app to help you pick clothes makes it feasible to mix and match items by letting you take a picture of the clothing item or friends, family, a salesperson can always be counted on. Closets can be managed by coming up with a labeling system, asking a friend to help label out clothes according to color, so the closet is organized by items that go together.

  • Cooking Meat - Food safety experts attest that color to judge if the meat, steak, roast, pork chops are cooked isn't the best way to go about it. One's best bet is to stick to the thermometer and a chart that shows the right temperature for cooking different meats.

  • Traffic Lights - Relying on position and not color is key. Top indicates stop Middle indicates caution – when the light's about to change Bottom indicates to go.

  • Dealing with color blindness in the classrooms - Where color recognition is needed, pictures can be labeled with symbols or words. Colored writing materials, for example, pencils, crayons, and pens can be labeled with color names for recognition. White chalk on a blackboard could be used to maximize contrast.