7 Noteworthy Types of Color Blindness Affecting Color Vision
August 9, 2024 • 6:15 PM
While it’s not especially common, color blindness affects one in 12 men and approximately one in 200 women. Depending on which form of color blindness you have, your vision may only be impaired to a slight degree.
Color blindness, also called color vision deficiency (CVD), makes colors appear differently to some people.
We’ll discuss the seven different types of color blindness and what treatments are available for people with these types of vision issues — but first, let’s start by talking about how vision (and our perception of color) works.
How Do We Perceive Color?
The visual process happens in fractions of milliseconds — light reflected off an object enters our eyes through the cornea, and the pupil helps focus this light back to the retina. The retina is located in the back of the eye and is home to our photoreceptors or vision cells.
There are two types of vision cells: rods and cones.
Rods help us see images in low light but do not help us perceive color. For example, if you see a car in only moonlight, you’d be able to see the car, but not necessarily its color, make, or model. Cone cells help us see images when more light is present.
Our retina cells collect the wavelengths of light from objects we focus on. The retinal cells then convert this light information into electrical signals, which are sent to the brain via the optic nerve. The brain then tells us the colors and objects we see in front of us. If these cells aren’t working properly, your vision will be impaired.
Cone Cells and Color
A person with normal color vision is said to have trichromatism, or the ability to perceive three specific cones of color. These are red cones (L-cones), green cones (M-cones), and blue cones (S-cones).
The amount of each color cone cell that is activated when we look at an object tells our brains what colors we see. The wide range of colors around us are all variations of these three combinations.
Color blindness is a condition that causes one or some of your cone cells to function incorrectly. While you may think that color blindness causes someone to be unable to see any color at all, the most common types of color blindness affect color perception — the way we see different shades of colors — rather than leading to an inability to see any colors.
What Are the Seven Types of Color Blindness?
There are seven common types of color blindness that can affect how a person perceives color. When you have your yearly eye exam, your doctor will likely administer a color blind test like a classic Ishihara test. Identifying the numbers in those multi-colored circles helps your doctor determine if you have color impairments.
The first four types of color blindness deal with a limited function of the types of cones that see green and red light.
1. Deuteranomaly
The most common form of color blindness is red-green color blindness, also known as deuteranomaly or protan/deutan color blindness. This type of red-green color vision deficiency makes green colors appear red.
Deuteranomaly does not affect all green colors, but many shades of green will appear red or have a red hue. A person with deuteranomaly has M-cones (which detect green light) that are present but weak.
2. Deuteranopia
Another form of red-green color blindness is deuteranopia. In this case, a person’s M-cones are entirely missing, which makes it impossible to distinguish green colors. Instead, green appears as beige.
3. Protanomaly
Another form of red-green color deficiency is protanomaly. This makes certain shades of red look green and also causes them to appear less bright than they actually are.
A person with protanomaly has L-cones (the ones responsible for long wavelengths, in this case, red light) that are red-weak. Shades of red may appear more green and less bright.
4. Protanopia
A person who has protanopia has L-cones that are missing entirely. This causes them to be unable to distinguish red from green, and red colors may appear dark gray or shaded.
Both of these types of color blindness are usually mild and don’t interfere with a person’s day-to-day life. However, it can make it nearly impossible for them to tell the difference between red and green.
As such, people with these forms of color blindness must be hyper-aware of the specific threats associated with their type of CVD. For instance, if you pull up to a red light, you’ll need to know the placement of the traffic lights (green at the bottom, yellow in the middle, red at the top) to know when to stop and when to go.
5. Tritanomaly
A less common form of color blindness deals with yellow and blue light. Blue-yellow color blindness makes it hard to tell the difference between important color combinations. A person with tritanomaly or Tritan has weak S cones that don’t function properly, making it hard to distinguish between blue and green or red and yellow.
6. Tritanopia
This form of yellow-blue color blindness makes it hard for someone to tell the difference between blue and green, purple and red, and yellow and pink. This is a more severe form of color blindness and affects how bright colors appear. A person with tritanopia has no S-cones.
7. Monochromatism
Sometimes referred to as total color blindness, monochromatism, also known as monochromacy or achromatopsia, makes it impossible for a person to perceive any color.
One caveat is that this isn’t technically considered a form of color blindness but rather a severe vision impairment. People with CVD have the ability to see color; they just have trouble distinguishing it.
People with monochromatism have a genetic abnormality that also impacts their ability to see clearly. This type of vision impairment is incredibly rare, and it’s unlikely you’ll have it unless someone in your family does.
Although CVD causes vision impairments, most colorblind people do not have trouble living life and quickly adjust to their vision deficiency. Because most color blindness occurs due to genetics, most colorblind people do not know any other way to perceive the world.
How To Treat Colorblindness
There is currently no cure for colorblindness, but tools are available to help people with it see the world more vividly. The most commonly used tools are color-blind glasses and color-blind contact lenses.
These specialized glasses and contact lenses filter out specific wavelengths of light, making it easier for a person with color blindness to differentiate between certain colors. They’re usually tinted and can be hard to find if someone needs other parts of their vision corrected.
Contact lenses with tints are also available. They typically offer a more solid solution for people with color blindness because they can be worn more comfortably and ensure that color correction covers the entire cornea.
In addition to tinted glasses and contacts, visual aids are available to help people with color blindness. Software options and apps can change the color settings of computer screens and devices to make colors easier to identify and see.
Although most people will never experience an issue with color blindness unless they inherit it at birth, these options are available to help color blind people experience the world more comfortably.
How Can Glasses Help?
You may be surprised to learn that many people who have CVD opt out of color-blind glasses. They have already adapted to how they see the world and don’t find it necessary to use a device.
In fact, some may find color-blind glasses more challenging to adapt to than living with the color blindness they’re already used to.
If you have a vision issue besides color blindness, you’ll probably need corrective lenses. These lenses correct for refractive errors like nearsightedness, farsightedness, and astigmatism. It’s possible to have a CVD and a refractive error (or several). You’ll need an eye exam to determine if you have any other vision-related issues.
Thankfully, modern advancements in eye care have made it possible for us to correct our vision and see more clearly. Once you’ve got your vision prescription, you can shop for frames and lenses wherever you’d like.
Pair Eyewear offers a unique take on vision care and style. Our Base Frames are stylish, durable, and surround lenses that can be customized to your prescription. Our Top Frames snap onto your Base Frames to give you a completely new style and look every time you change them. One set of frames can give you unlimited possibilities.
Manage Color Blindness
How you see the world may differ from others, but it’s never held you back. Now, you can see your world through new, exciting frames that perfectly complement your sunny personality and style. Pair Eyewear makes it easier than ever to get the eyewear you need in a style you’ll love.
Sources:
Types of Color Vision Deficiency | National Eye Institute
How Humans See In Color | American Academy of Ophthalmology
Achromatopsia: Color Blindness and Other Vision Issues | Cleveland Clinic