What Does Being Color Blind Mean?

Being “Color blind” doesn’t mean you only see shades of gray. It is extremely rare to be completely color blind (that is, you only see black and white).

For this reason, “color vision deficiency” (CVD) is a more precise term for color blindness. To have CVD means colors are visible but in other shades and intensities than normal.

Approximately 8% of men and 0.5% of women worldwide suffer from CVD. You can take this Color Blindness Test to check whether you are color blind or not.

How Do You See Color?

It is difficult to understand with 100% accuracy what your world would look like if you had a color vision deficiency. Even if you sense something as red, it may not be the same shade and intensity as the glimpse of the red other.

A signal is transmitted to your brain when the lens inside your eye focuses light/color wavelengths on the retina. There are millions of cells present in your retina called photoreceptors. Cones and rods are the two types.

  • Cones 

These cones control your color vision. There are many different pigments present in cone cells called photopigments. The photopigments respond to different incoming wavelengths of light/color and send signals to the brain. 

All photopigments must be present in your cones to see every color in the spectrum. If you are missing a photopigment you will see a lessen color spectrum.

  • Rods 

Rods only have one type of pigment that responds the same to various light wavelengths. Rods don't contribute to your color vision. But they are very sensitive to light and help with your night vision.

How Do You Become Color Blind?



Color Vision Deficiency is usually hereditary. If you have a family member who is color blind then there is a chance you or someone else in your family will inherit the gene.


Certain chronic diseases can ultimately lead to color deficiency. A few common illnesses include Alzheimer’s disease, liver disease, glaucoma, chronic alcoholism, leukemia, multiple sclerosis, and Parkinson’s disease

Severe Accidents 

An accident resulting in severe trauma to the eye or a stroke that damages parts of the brain can lead to the development of a color vision deficiency.  


Antibiotics, high-blood pressure medications, and medicines used to treat nervous disorders can potentially produce a color vision deficiency over time.  

Chemical Contact 

Industrial or environmental chemicals can make you color blind. Chemical like Carbon monoxide is some common contributors.  

A Closer Look At Inheritance

Almost all CVD is inherited. However, specific diseases can raise your risk of developing color vision deficiency:

  • Glaucoma
  • Diabetes
  • Chronic alcoholism
  • Leukemia
  • Alzheimer’s disease
  • Parkinson’s disease
  • Macular degeneration

Specific drugs may also raise your risk of developing CVD. Hydroxychloroquine (Plaquenil) is an example used to treat rheumatoid arthritis.

Types Of Color Blindness

Types Of Color Blindness

Red-green Color Blindness

Red-green color blindness occurs when the red or green photopigments in your cone receptors don’t work correctly or are absent. Red-green color blindness is more commonly found in men. 

The gene that causes red-green color blindness is located in the X chromosome

There is one X chromosome in men and two x chromosomes in women. 

In women, the stronger X chromosome is generally dominant, and normal color vision is maintained.

Blue-yellow Color Blindness

Blue-yellow color blindness happens when there is an issue with the blue or yellow photopigment receptors. This is an extremely rare type of color blindness — making up only 5% of color vision deficiencies. 

The possibility of having blue-yellow color blindness is equal in men and women. The damaged gene, on chromosome 7, is shared by men and women equally.

Symptoms Of Color Vision Deficiency

The symptoms or signs of color deficiency vary. In mild cases, you may not be aware of your color blindness. Because in most cases persons are born with this deficiency.

Other symptoms include

  • Problem seeing colors
  • The colors do not seem as bright
  • Inability to determine certain shades of the same or similar colors
  • Using the wrong colors when drawing an object (such as making the purple leaves on a tree or the orange grass)
  • Problems recognizing red or green crayons, paints, markers, or any colors, such as purple and brown, that contain red or green pigments
  • Difficulty recognizing colors in low light
  • Sensitiveness toward bright lights
  • Difficulty in reading from coloring pages
  • Complaints of eye aches or headaches when glancing at something red on a green background, or vice versa
  • Not wanting to color in paintings or play counting or sorting games with colored entities

Diagnosing Color Vision Deficiency

Your eye doctor uses a simple examination to diagnose CVD, called the Ishihara test. The test consists of a sequence of colored plates with numbers and patterns you are asked to recognize. 

If you have color blindness you will not be able to see all the numbers and patterns present in the center of the plate.

Other than the Ishihara test there are some other tests like the Cambridge color test, Anomaloscope Color Blindness testFarnsworth-Munsell 100 hue test, and Farnsworth lantern test.

Challenges Come With A Color Vision Deficiency

Most individuals who have a color vision deficiency have adapted to their unique color spectrum. Although certain levels of color vision are a requirement for some professions including police, pilot, and electrician. Other challenges include:

  • Identifying traffic lights, especially in the distance
  • Considering the ripeness of the fruit
  • Reading metro maps & Graphs, Matching clothes
  • Easily identifying products (e.g. Gatorade flavors, or Snack chip flavors)
  • Having to ask a stranger for assistance with colors.
  • Keeping color blindness a secret, mainly at work
  • People not believing you when you tell them you're colorblind
  • Repeatedly asked, “what color is this?”
  • Playing most video games without colorblind mode
  • Electrical devices switch from red to green when completely charged
  • Using colors as the only identifiers for things. 'Can you hand me the red one?'
  • Picking out makeup and applying it.
  • Restricted careers for people with color deficiency

Cure For Color Blindness

There is no cure for hereditary color vision deficiency now. Special contact lenses and glasses may assist with some color vision deficiencies. For acquired deficiencies, your eye doctor will address the underlying condition or drug that is causing the issue.

Color vision is routinely evaluated at your complete eye examination. However, if you detect a sudden change in your color vision you should see your eye doctor.