October 18, 2022

What Is Color Blindness: Everything You Want To Know

Many people do not understand color blindness (or color blindness for our readers across the pond). In movie depictions of dogs, we see only black, white, and gray. It's much more complicated than that with color blindness (in humans and dogs). If you to want test your eyes color blind test helps you to determine color deficiency, reveals red, green or blue color blindness or any kind of color vision weakness.

The purpose of today's discussion is to review the types of color blindness, the causes, and the treatment options available.

What Is Color Blindness?

To understand color blindness, we first need to know how the eye works. As light enters the eye through the front (lens), it is focused on the retina (back) of the eye. The retina is made up of pigment-containing nerve cells called photoreceptors. Your rods and cones look like this.

Color vision isn't related to rods; they respond to all colors of light the same way. The rods in our eyes contribute to our night vision because they are very light-sensitive!

Today, we need to focus on cones. You have three types of cone cells that control your color vision. These cone cells react differently to light wavelengths because of their pigments:

  • Short wavelengths (blue)
  • Medium wavelengths (green)
  • Long wavelengths (red)

Color blindness is caused by pigments in the cone cells not responding properly (or at all).

What Are The Different Types Of Color Blindness?

In color blindness, the cone cells in your eye are deficient. This leads to color blindness, which is also known as "color vision deficiency."


Approximately 60% of your cones are red-sensitive, 30% are green-sensitive, and less than 10% are blue-sensitive. Accordingly, a patient's color blindness will vary based on whether red, green, or blue cone cells are affected.

Red-Green Color Blind

The most common cause of this is problems with your red or green cones. Color blindness is most commonly caused by red-green vision deficiency.

Approximately 8% of men and 0.5% of women suffer from red-green colorblindness.

You can suffer from red-green color blindness in multiple ways, as your green and red cones may malfunction independently.

Deuteranomaly

Most of the time, color blindness affects men, which affects 5% of the population. Color blindness caused by a malfunctioning green cone is called deutan color blindness. The color yellow is made reddish and green is made of violet, and the color green is made of blue.

Protanomaly

The red cones do not function properly when you have protan color blindness. There is usually mild color blindness associated with this type. The colors orange, red, and yellow appear greener, and overall, they are less vibrant.

Protanopia

The red cone cells in your eye don't work at all. The color red looks gray, while the colors orange, yellow, and green look yellow.

Deuteranopia

Green cone cells aren't functioning at all. The color green looks beige and the color red looks brownish-yellow.

Blue-Yellow Color Blind

Tritan color blindness affects only one in ten thousand people, and it affects both men and women equally. In addition to being inherited, blue-yellow color blindness is more likely to be acquired later in life from eye diseases such as glaucoma, cataracts, macular degeneration, retinopathy, or other illnesses that affect the optic nerve and retina.

Blue-yellow color blindness can be divided into two types.

Tritanomaly

In this type of color blindness, the blue cones have a change in color sensitivity. Tritan color-blind people tend to confuse blue and green, as well as yellow, orange, and red.

Tritanopia

The blue cones don’t work at all.

Complete Color Blindness

The previously listed forms of color blindness are “anomalous trichromacy” or “dichromacy.” That is, still having all three color rods, but with some malfunction or only having two color rods functioning.

There are, however, more advanced forms of color blindness, such as:

Cone Monochromacy

It occurs when there are two nonworking pigments in cone cells.

Achromatopsia

Color blindness is a total lack of vision in color. In addition to seeing in shades of black, white, and gray, people with complete achromatopsia may also experience other vision problems.

How To Tell If You’re Color Blind

It depends on the severity of color blindness and what the symptoms are. Some people don't even realize they have a color perception deficiency because their symptoms are so mild.

For the most part, color blindness does not affect the sharpness of vision. Primary symptoms of color blindness include:

  • Trouble seeing colors or brightness of colors
  • Inability to tell the difference between shades of the same or similar colors (most commonly with red and green or blue and yellow)

Ask your eye doctor about a color vision test if you suspect you might be color blind.

What Are The Symptoms Of Color Blindness?

Normally, children may take a color blind test as part of a regular eye exam, especially if they are at risk of color blindness.

There is a good chance you have seen images from the Ishihara color test, even if you have never taken a color vision test.

In these fields of colored dots, patients with normal color vision can make out the numbers hidden within them. The color-blind will either not be able to see the numbers or will see them differently (depending on the image). In this way, the eye doctor can determine the type and severity of color blindness in a patient.

What Are The Causes Of Color Blindness?

It has been said that color blindness is a genetic condition. As an X-linked recessive gene, it is carried on the X chromosome and passed along through families.

The majority of colorblind people are born with the condition. It can, however, develop later in life if a person is suffering from health issues. Some non-genetic causes of color blindness include:

Eye diseases
Diabetes
Alzheimer’s disease
Parkinson’s disease
Multiple sclerosis
Chronic alcoholism
Leukemia
Use of certain drugs, including hydroxychloroquine

Why Color Blindness Is More Common In Males

If you remember high school biology, you probably remember that (generally) people either have XX chromosomes or XY chromosomes. Color blindness is caused by a gene that is carried on the X chromosome. People who have two X chromosomes are more likely to carry the gene without showing symptoms.

Due to color blindness being recessive, the color blind gene must be present on both X chromosomes to be color blind. Otherwise, the dominant normal color vision gene will overwrite the color blind gene.

Most men, however, only have one X chromosome, which means they only need one color-blind gene.

According to a 2014 study, white people are also more likely to suffer from color blindness. A study published in the American Academy of Ophthalmology's Ophthalmology journal examined the issue of color vision deficiency in preschoolers. According to their study, color blindness affected 6% of white boys, 3% of Asian American and Latino boys, and 2% of African American boys.

Is It Possible To Cure Color Blindness?

In the case of genetic color blindness, there is no cure. Although it may negatively impact your day-to-day life, there are ways to mitigate it.

Many important things in life can be worked around by people who are colorblind (traffic lights, stop signs, etc.). When you cannot distinguish between red and green, traffic lights will always be displayed in the same order. Stop signs are all red, but they have distinct shapes as well.

There are smartphone apps that can identify colors for "less important" distinctions (do these clothes match? which pen is red?)


The use of color-blind contact lenses and glasses has exploded in recent years. Even the National Eye Institute has published research on color-blind glasses. Depending on the severity of your color blindness, these devices can help you recognize colors (although they won't cure it).

You may be able to resolve your color vision problem if you developed it later in life due to a disease.

How Color-Blind People See

A person who has normal color vision may find it difficult to imagine what color blindness is like. The magic of technology has enabled us to develop color blindness simulators!


If you are a designer, want to make your website or product more accessible to color-blind customers, or are just curious, you can use websites and browser plug-ins to simulate what colorblind people see.