The average person has the ability to perceive millions of different colors due to the presence of a few different types of cones in the retinas that send color messages to the brain. However, there are some people who are missing cones or have cones that are faulty. Because of this, their color perception is significantly decreased. This condition is referred to as color blindness and it affects approximately 0.5% of women and 8% of men. Some people are not aware that there are many types of color blindness and that each type will impact a person’s ability to perceive colors, differently.
What is Red/Green Color Blindness?
Regular color vision is referred to as trichromacy-tri, since it involves three correctly functioning cones that allow a person to see millions of brilliant shades of color. If one of these cones is taken away, then the number of possible color combinations a person is able to see drops down to just ten thousand. Many people affected with color blindness are men since the genes that involve color vision are on the X-chromosome. Unfortunately, men only have one of these chromosomes. Red/green color blindness is the most common form and it’s actually a grouping of many disorders that have a similar impact on vision.
The reduced sensitivity to red colors is due to a defective or missing longwave cone and it’s known as protanopia. The reduced sensitivity to green colors is caused by a defective or missing mediumwave cone and the condition is known as deuteranopia. Both types will cause issues with distinguishing between oranges, greens, and reds, and can cause yellows and blues to stand out.
Red/green color blindness is actually just a generic term that’s used for any type of red-blind or protan and green-blind, or duetan color vision deficiency. So, what’s the difference between these two and why are they grouped together?
The main axis of color confusion is relatively the same, as is the fact that both types share the same main problem colors: brown, green, yellow, orange, and red. Additionally, genetic information is also located on the X-chromosome. However, there are some differences that make splitting green-blind and red-blind people into a couple of different groups.
People with red-blind color blindness will perceive red much darker. Additionally, the colors of confusion in the purple and blue areas of the color spectrum will also be different. People with red-blind color blindness will have an easier time identifying purples and blues.
But considering the close similarities between these two types, it comes as no surprise that glasses designed to treat red/green color blindness will work for both red-blind and green-blind people.
What is Blue/Yellow Color Blindness?
Weakened or missing shortwave cones results in a condition called tritanopia. This type of color blindness is incredibly rare and only affects approximately one in fifty thousand people. This condition impacts the person’s ability to distinguish between greens and blues and some yellows. Contrary to red/green color blindness, this type will affect both men and women equally, whereas red/green color blindness more commonly affects men.
People with tritanopia typically have fewer problems when it comes to performing tasks, compared to people with red/green color blindness. This is mainly because red and greens are used more commonly in society. Additionally, this type is not only inherited, but it can also be acquired at some point in life. When acquired later in life, it can be reversible if there has been no permanent damage.
What is Total Color Blindness?
There are some people who have a severe form of color blindness that prevents them from seeing any colors. Basically, they view the world as though it were a black and white movie. This type is called monochromacy and it’s caused by an absent or non-functioning retinal cone. This type is very rare and will only occur in one out of thirty-three thousand people.
Diagnosis and Treatment
Color blindness is mainly inherited, however, color vision defects can be caused by certain medications, chemicals, accidents, injuries, and illnesses. Unfortunately, there’s no cure for color blindness, however, there has been some progress noted in gene therapy research. If you’re concerned that you may have a form of color vision deficiency, make an appointment with your eye care specialist. Your doctor can run some tests which will determine whether or not you have some form of color blindness, and if so, what type.
How Color Vision Works
In order to see colors, we need help from the photoreceptors in the eyes. There are a couple of different types: cones and rods. Both types sit on the retina, passing information of light to the brain. There are approximately one hundred and twenty million rods which are very light sensitive, but not sensitive to colors.
Cones are a type of photoreceptor that’s responsible for color vision, these cones gather together very closely in the retina’s center. Each cone reacts differently on colored light sources and carries out one of three different photopigments. With each type of cone, there exists a specific color absorption curve that will peak at a different point in the color spectrum.
- S cones are sensitive to short-wavelength lights
- M cones are sensitive to medium wavelength lights
- L cones are sensitive to long-wavelength light.
Mixing the information together from these three different types of cones is what makes up a person’s color vision. Additionally, it’s the reason that only a few main colors are needed if you want to mix together all visible colors since a person only has three sources of information when it comes to mixing the whole color spectrum.
Early Symptoms of Color Blindness
While the symptoms of color blindness can vary from person to person, below you’ll find a list of early signs that you or your child may be suffering from a color vision deficiency.
The main and most common symptom of color blindness is the difficulty in distinguishing between colors. Many people affected by color blindness will also make mistakes when trying to identify a color. If you suspect you or your child are suffering from color blindness, there are some other signs and symptoms you can look for:
Choosing the wrong color for a specific object. As an example, your child may color the leaves on a tree purple instead of green.
- When participating in coloring activities, a child may have a very low attention span
- They may deny color issues
- They will have difficulty identifying green or red crayons or any crayon that has green or red in its composition, such as browns and purples.
- The ability to identify certain colors can be made worse in low light conditions
- A child may smell their food before eating it
- They may have a better than average sense of smell
- People affected by color blindness also tend to have better than average night vision
- Some people with color blindness have a hypersensitivity to bright lights
- Children may struggle to read worksheets or pages with colored words
- Adults and children with color blindness will often complain about headaches or eye strain, which is common if they’re struggling to identify colors while watching a movie, coloring, putting together a puzzle, or using the computer
If you’re concerned that your child may have a color vision problem, don’t wait to seek treatment. If there are any men with color blindness on the mother’s side of the family, such as grandfathers, uncles, or cousins, your child will be at risk. By the age of five, children that have normal color vision should be able to easily identify all the major color groups. Children who are color blind may appear to be able to do this, but it will take them significantly longer to identify colors.
A Simple Color Blindness Test
If you want to determine whether or not your child has a color vision problem, take out a white sheet of paper and give them crayons in at least twelve different colors, including shades of grays, purples, blues, oranges, browns, reds, and greens. Make sure you use mid-range shades, which means the colors shouldn’t be too dark or too pale. Shade an area of the paper using each color. Make sure that the colors have been placed in random orders, so avoid putting greens and reds together. Make sure you also place browns, greens, and reds, adjacent to each other.
Try this test out in an area that has good natural light and avoid using artificial light or being in an area with strong sunlight. Now, make up a game that involves asking your child to name each color on the sheet. Avoid showing them each color individually. Instead, they need to see all of the colors at the same time. If they show signs of uncertainty when attempting to identify certain colors, then they may have color vision problems. To confirm whether or not your child is color blind, make an appointment with their eye care specialist.
Color Blind Glasses
If you have color blindness or another member in your family does, then you may have heard about glasses that are designed to treat color blindness. But do color blind glasses really work? Yes and no. Even the best color blind glasses will not work for everyone. Essentially, these glasses are only designed to treat people with red/yellow color blindness, which as you remember, is the most common type. People with other types of color blindness will not benefit from use. In terms of how effective they are, while they cannot cure you of this condition, they can work for some people. A person who uses these glasses may not be able to see colors in the same manner as someone with regular vision, but they will be able to experience colors like never before.
The lenses in these glasses will rely on color vision science and the latest optical technology in order to allow the wearer to experience colors differently and help them to distinguish between greens and red. These glasses may not cure the wearer but they can have a major impact on how bright these colors are. The lenses are equipped with a filter that targets certain types of photopigments that are responsible for cutting out select wavelengths of light, in order to enhance certain colors. These lenses will divide the overlapping green and red hues, which will improve the color vision for people affected by this specific type of color deficiency.
There are glasses available for both indoor and outdoor use. The indoor glasses come with lens filter technology that will enhance a person’s color vision when they’re in low light settings. Outdoor glasses will enhance color vision and can block out harmful UVB and UVA rays, so a person can distinguish colors easily, in bright light conditions.
Color Blindness Facts
- Most people believe that a person who suffers from blue/yellow color blindness is not able to distinguish those two colors. However, this is not correct. Color blindness does not relate just to a couple of color hues, it involves the whole color spectrum. This means a person will not be able to see any color that has even a hint of blue or yellow hue to it.
- Color blindness is genetic and can be passed on from parents to their children. Women who are red/green color blind will have sons that are red/green color blind.
- Ninety-nine percent of color blind people suffer from red/green color blindness
- This color vision deficiency can also be caused by aging, damage to the retina, and eye diseases
- The test that’s the most widely used to test for color blindness is called the Ishihara test and it was created by Dr. Shinobu Ishihara who was an ophthalmologist. The test consists of plates that are filled with colored dots. These plates contain different colors of dots that are shaped like numbers. A person with color blindness will not be able to see these numbers.
- There are some countries that will not allow a person with color blindness to drive because it can be difficult for them to distinguish between the different traffic light colors
- A person with color blindness will not even be able to see certain colors in their dreams
There are many types of color blindness. Unfortunately, there is no cure for color blindness that’s genetic. Color vision problems that are caused by injuries or medications can be reversible in some cases. Now that you know more about color blindness, the different types, the common signs, and how to determine if you or your child are suffering from color vision problems, you can speak with your eye care specialist if you suspect you or another member of the family is affected by this condition. While being color blind can be very challenging for some people, especially those affected by rarer types, it is totally possible to live a normal life by making some simple adjustments.