Color blindness, also known as color vision deficiency, is the decreased ability to see color or differences in color. Color blindness can make some educational activities difficult. It can also prevent you from passing certain tests and achieving certifications that include the ability to distinguish between colors as a requirement.
What Causes Color Blindness
Color blindness is a defect in the way we see and distinguish colors.
Color blindness is a defect in the way we see and distinguish colors. It is a genetic disorder, which means it’s usually passed down from parents to children. While it may seem like an easy way to get out of being wrong when you can’t tell whether something is blue or green, colourblindness affects nearly 10% of all men and 0.5% of all women worldwide—so chances are you know someone who has it or had it at some point in their lives!
Some people think that if they’re colourblind, they’ll never be able to drive or do other things that require seeing different shades and hues of light. But this isn’t true! Colour blindness doesn’t mean that you can’t distinguish between reds and greens; rather, it means that sometimes your brain interprets them differently than other people do.
There are several different types of colour blindness.
Color blindness, which is usually inherited, may be present at birth or develop later in life. There are several different types of color blindness:
- Red-green color blindness, the most common and widespread type, is caused by an absence or malfunctioning of red pigments in the retina. It affects up to 8 percent of men and 0.5 percent of women worldwide.
- Blue-yellow color blindness involves an inability to see blue or yellow hues; this form is much rarer than red-green color vision deficiency because these colors don’t contain as many wavelengths (the light waves that can be perceived by the human eye) as others do—but it’s still thought to affect around 1 in 12 men and 1 in 200 women worldwide.
- Total color blindness (or monochromacy) occurs when there’s a total lack of any cone cells; this condition affects less than 1 percent of people on Earth, regardless of gender or race/ethnicity!
Colour blindness can also be partial; for example: If a person only has problems perceiving certain shades within one color spectrum but not another—like someone who can tell all greenish blues apart from purplish reds but has difficulty distinguishing between shades that fall between those two points along the spectrum—then they would have “red–green” partial tritanopia instead if full tritanopia were present (in other words).
Color blindness can run in families, since it’s usually genetic.
Colour blindness can be inherited. Color blindness is a sex-linked trait, which means that the gene responsible for it is located on the X chromosome. Women have two X chromosomes, and men only have one. Because of this, color blindness is usually inherited from women in families who have a history of color vision deficiency (CVD).
In families where both parents are carriers of the same defective CVD gene and pass it on to their child during conception, there’s a 25% chance that their child will inherit two copies of that defective gene—one from each parent—and be affected with true monochromacy or total color blindness. In general though, when people say they’re “color blind”, they’re actually referring to partial CVD; most cases fall somewhere between mild or moderate deuteranomaly and severe deuteranopia or protanopia.
Red-green color blindness is the most common form and is caused by a mutation to the X chromosome. Blue-yellow color blindness, which affects less than 1 percent of men, is caused by a mutation in the OPN1LW gene on chromosome 3. Total color blindness, which affects less than 0.005 percent of men and women, occurs when both copies of the X chromosome are mutated for either red or green opsin genes (OPN1MW on chromosome 7). For this reason, it’s usually passed down through families as an autosomal recessive trait along with other typical red-green defects such as protanopia/protanomaly (red-blind) and deuteranopia/deuteranomaly (green-blind).
Total color blindness can also affect some women who have only one healthy copy of their X chromosomes; however this type isn’t passed down from parent to child because they were born with two working copies instead!
Red-green color blindness : caused by a mutated X chromosome.
Red-green color blindness (also known as deuteranomaly) is caused by a mutated X chromosome. It is linked to a recessive gene on chromosome 7. This means that for the condition to be present, you must have at least one copy of the mutated gene from your mother and another from your father, who may or may not have it themselves.
It’s important to note that this type of color blindness is not necessarily passed down by both parents equally; it can skip generations before appearing in someone’s family tree.
In some cases, red-green color blindness can be inherited through both father and mother but only if they each carry one copy of the mutated gene which they pass on together—which means two copies total within one family member!
Blue-yellow color blindness : caused by a recessive gene on the X chromosome.
Blue-yellow color blindness is the most common form of color blindness. It is caused by a recessive gene on the X chromosome, meaning that it is only passed on by females. This means that while men are affected by this form of color blindness, they rarely have children with their wives who have blue eyes.
Total color blindness : caused by a recessive gene on chromosome 7.
If you are completely color blind, your vision is monochromatic. You see everything in shades of grey.
Total color blindness (achromatopsia) affects less than 1 in 30,000 people and is the rarest form of color blindness. In this condition, you have no ability to discern differences in reds, greens, and yellows/golden browns (which correspond to long-wavelength cones). This type of total color blindness can occur with red-green color vision deficiency or blue-yellow color vision deficiencies; however it’s more likely when both genes are defective on chromosome 7.
Achromatopsia occurs because one of the three opsin genes has a mutation that prevents proper development of your retinal cells so there is no cone cell photoreceptors for wavelengths at about 500 nm (blue), 550 nm (green), 560 nm (yellow), or 590 nm (red).
Color blindness can be caused by physical injury
A physical injury to the eye can also cause color blindness. This type of color blindness is called organic or acquired, as opposed to inherited (genetic) or congenital (present since birth).
For example, a chemical burn to the retina can affect how light enters the eye and therefore how colors are perceived by people with this condition. Similarly, being struck in the head can cause bruising on the retina which will alter perception of colors for a short time after impact.
Color blindness can be caused by medication.
It’s not uncommon for medication to cause color blindness. Most commonly, this occurs when a person has a condition called metachromatic leukodystrophy (MLD). MLD is an inherited genetic disease that can lead to damage of the optic nerves and central nervous system if left untreated. It can also lead to a variety of symptoms, including:
- difficulty with balance or walking
- motor skills impairment (difficulty with movement)
- lack of coordination and fine motor control (the ability to use small muscles)
- weakness in arms or legs
Color blindness doesn’t mean you can’t see any colors at all.
Color blindness is a spectrum, from mild to severe. A person with color blindness may be able to see some colors but not others, or they may be able to detect different shades of similar colors but not the difference between those shades.
It’s also possible that a person with color blindness will be unable to tell the difference between certain colors at all. This is called monochromacy—a condition where you only see in shades of black and white (or grays). Monochromacy isn’t common, although it does occur in about one in 30 men.
In spite of this variation in severity, people with color blindness are often still able to recognize basic shapes—like squares and circles—even if their ability to name them is impaired by their condition.
Color blindness doesn’t affect your ability to see shapes or black and white images.
If you’re red-green color blind, you might not be able to tell the difference between a green light and a red light. But you can still see lights as different shades of gray—you just can’t see that they’re different colors. You’ll also have no trouble telling apart objects with similar colors (like an apple versus a pear).
A new study in Denmark that appears in the journal Ophthalmology suggests that people with color blindness may be more at risk for other health issues.
The study, which tracked more than 3,000 men for about 50 years, found that men diagnosed with red-green color blindness were up to 4.5 times more likely to develop glaucoma than men who weren’t colorblind, according to the Los Angeles Times.
People who are diagnosed as completely color blind are more likely to develop glaucoma than people with milder forms of colorblindness, NPR reported.
And women in general may be less likely than men to develop glaucoma. In the Danish study, women had lower rates of glaucoma no matter what their level of colorblindness was, the Los Angeles Times reports.
For example, people who are “red-green color blind” — they can see a range of colors but have trouble distinguishing between red and green — are also more likely to have cardiovascular problems and are at higher risk for developing diabetes, according to NPR’s report on the Danish study.
While our brains interpret light from the back of our eyes through an elaborate system called the visual cortex, other nerves send signals from the eye’s retina directly to another part of the brain called the thalamus, which processes and interprets visual information.
Ways for Treatment of Color Blind
Colorblindness is a fairly common condition, but it’s rare for people to have no color vision at all. Some may have limited color vision.
Colorblindness can be treated in several ways:
- Colorblindness can be treated with glasses or contacts. Glasses with special tints are the most common treatment for mild to moderate cases of colorblindness. Lenses that filter out certain colors of light can also help. If your doctor finds that you have very severe difficulty distinguishing between red and green objects, he or she may prescribe contact lenses designed specifically for people who are colorblind.
- Colorblindness can be treated with surgery as well as more conventional methods such as glasses or contacts. This kind of surgery involves removing some cells from the retina (the light-sensitive layer at the back of your eye) and replacing them with clear material that lets light pass through but blocks out certain wavelengths (colors). This procedure allows you to see shades of gray rather than individual colors, though they’ll still appear different than they would if you could see them properly in their true hues — reds will appear darker than oranges, blues lighter than violets — so it can take some getting used to!
Who Is At Risk For Color Blindness
When someone says they are colorblind, they typically mean they can’t see some colors. In reality, the term “colorblind” is a bit misleading, since it suggests there are only two types of people: those with normal vision and those with the condition. In reality, there are several different forms of color blindness. And while it’s easy to assume that only men have this condition (since on average more men than women suffer from it), that’s not always the case. So who is at risk for color blindness?
Men are more likely than women to be color blind.
Men are more likely than women to be color blind. A 2004 survey of over 4,000 people found that men were twice as likely as women to have a red-green color deficiency. The same study also showed that children with a color deficient parent were four times more likely to be affected themselves.
Each type of color blindness has different genetic associations.
Each type of color blindness is caused by a different genetic mutation. Red-green color blindness is the most common type because it’s inherited from your mother, who carries an X chromosome that contains the mutation. Color blindness can also be caused by mutations on other chromosomes (like autosomal dominant), which are more rare but still affect millions of people worldwide.
Each type has different genetic associations and ethnicities associated with them:
- X-linked red-green color blindness affects only men and women with a mutated X chromosome; over 90 percent of cases are passed to boys from their mothers
- Color vision deficiencies (CVD) involving blue cone monochromacy usually result from one defective gene on chromosome 7; also known as protanomaly or deuteranomaly, it affects around one in every 30,000 people in the U.S., making it far less prevalent than X-linked red/green CVD
People with myopia have a higher risk of being color blind.
People with myopia have a higher risk of being color blind. Myopia is the most common type of color blindness, and it occurs when the eyeball is too long from front to back.
People with albinism may have a higher risk of being color blind.
Albinism is a genetic condition that causes a person to have little or no pigment in the eyes and skin. People with albinism may also have vision problems, such as farsightedness or nearsightedness.
The symptoms of color blindness can vary depending on the type of color blindness an individual has. For example, people who are red-green color blind will have trouble distinguishing between reds and greens; those who are blue-yellow color blind might be able to see some shades of purple instead of blue or green objects; and those who are total monochromat would see everything as varying shades of gray—but they may not realize there’s something wrong with their vision because they don’t know what colors look like in the first place!
Color blindness is usually inherited from either one parent (monoallelic) or both parents (diploallelic), but sometimes it’s caused by a mutation in just one gene for each eye (uniparental).
Some types of cataracts can cause color blindness.
Color blindness can also be caused by cataracts. A cataract is a clouding of the lens that occurs when the eye has been exposed to too much sunlight or as a result of aging.
Color vision problems may occur after surgery on your lens or retina, conditions which are more likely to develop in people with diabetes. If you have diabetes, it’s important to talk to your doctor about whether the condition may affect your color vision and how it’s treated.
Anyone can develop acquired color blindness.
Most color blindness is inherited. The genes associated with the rarer types of color blindness are passed down from one generation to the next. However, acquired (or transient) color blindness can happen at any time in life. It can be caused by trauma, disease or medication.
There are many misconceptions about color blindness, especially since it’s a condition that’s often misunderstood. While those of us with normal vision have no way to truly understand what it’s like to see the world through the eyes of someone who is color blind, we can still learn more about this condition. If you know someone who has difficulty seeing colors properly, don’t worry because they will be able to overcome this obstacle by using special glasses or contacts prescribed by an eye doctor.