It generally occurs when there is a problem with the part of your eyes that senses colors. Most of the people with this condition will find it difficult to distinguish green and red.

The less common type of color blindness would be the inability to differentiate blue and yellow.

Understanding what is color blindness and what causes it will help you cope up with your condition.

A Complete Guide on What is Color Blindness and What Causes it

Our eyes can discern the different wavelength of light that passes through it.

It’s like listening to noises around us wherein you can distinguish the light tapping sound and the loud knocking noise; we refer to this as pitches.

It indicates the sound frequency or the times the sound vibrate in a particular period. The tone from the left has the lowest frequency, and it increases as it moves to the right.

This concept can also be applied to colors. The various colors in the spectrum pertain to the distinct wavelength of the light. Blue have shorter wavelengths, and the red has a longer wavelength.

How Do Our Eyes See Colors?

You can picture out your eyes as the camera of your phone. It comes with a lens that helps us focus on a particular object, and the images will be transferred to the retina.

The retina contains cells that react to different wavelengths of light.


This cell contains a single type of pigment. It will react similarly to a variety of wavelengths of light.

This part will not have anything to do with discerning colors. However, it is highly sensitive to light that enables us to see even when in dim light.


This part controls the person’s color vision. Most of us will have three cone cells that have different types of pigments.

Some will respond to the short wavelength of light, and others will respond higher to longer light wavelengths.

Color Blindness: What is It?

When different types of pigments are present in our cones, our eyes will be able to discern all the possible colors.

However, if there are some problems with our photopigments, it may be difficult for us to distinguish some colors.

It is clinically referred to as color blindness or color deficiency. If a single pigment is missing, you may notice that it is difficult for you to perceive some colors.

For people who do not have photopigments in their eyes, they will not be able to see any kinds of colors.

What Are the Various Types of Color Blindness?

Perhaps the most common type of color blindness is caused by a genetic condition.

It happens when the genes that you have inherited from your parents that develop these photopigments are not functioning the way they should.

There are times that you will not be able to see specific colors and other times when you will not be as sensitive to colors like the others.

Red-Green Type of Color Blindness

This condition happens when the green cones and red cones in your eyes are not working correctly. There are also different sorts of this color blindness.


Probably the most common types of color blindness, especially on males wherein 5% of the male population have this. It rarely occurs among females.

It usually happens when the green cone will not work the way it supposed to. The yellow and green appear like a red shade, and it will be difficult to distinguish between violet and blue.


In this condition, your red cone is the one with a problem. The yellow, red and orange shade will appear greenish, and most of the colors will not look as bright as they should.

It is a mild problem and will not cause any harm to your life. It is also a rare condition among females and affects only 1% of the male population.


Your red cones are completely not working. Red will appear to you like a dark grey. Other shades like green, yellow, and orange will look yellow.


Here, the person will not have working green cones. The red pigments will appear brownish-yellow and green and beige will be indiscernible.

Blue-Yellow Type of Color Blindness

This condition is caused by your blue cone cells. The photopigments are either malfunctioning or missing.

It is the next most common kind of color blindness and affects both men and women population.


Blue cone photopigments are only working in a limited manner. The blue will appear greener, and it will be difficult to tell red and yellow apart. This condition is very rare.


This is the more common type of blue-yellow color blindness. Blue cone photopigments are missing. The yellow appears violet or light grey, and it is hard to distinguish green from blue.

Complete Type of Color Blindness

This color blindness is also referred to as monochromacy. Your vision will not be as clear as others, and you will not be able to distinguish any types of colors.

Cone Monochromacy

This condition can occur when 2/3 of your cone cells are not working. It means that only one cone cell photopigment is working.

In this instance, it will be difficult for you to distinguish one color from the other. In case one of the faulty cones is blue, you will notice that your vision is not sharp.

You may experience nystagmus or uncontrollable eye movement and nearsightedness in connection with this.

Rod Monochromacy

Also known as achromatopsia, this is a condition wherein none of your cone cells is working.

It is the most severe form of color blindness, and the world will look like a shade of grey, black, and white.

When exposed to bright lights, your eyes may get hurt. You may also have nystagmus together with this condition.

What are the Symptoms of Color Blindness?

People with color blindness will experience varying symptoms. Perhaps the most common symptom would be a noticeable change in the vision.

For instance, you may find it difficult to distinguish the difference in the color of the traffic light.

Some colors appear brighter before, but they seem bland now. You will also notice that different colors look the same.

Color blindness will usually be more apparent during your early childhood years. Your parents may notice it when you are just learning about colors.

Some people will associate colors to particular objects which makes it highly likely that their condition will be undetected.

For instance, they are aware that the grass and leaves are green. In some cases, the symptoms are very subtle, and they will not realize that they do not see some colors.

If you suspect that your child has this condition, it is best to consult the physician.

They can perform a diagnosis that will confirm your suspicion and rule out any possible medical condition.

How is Color Blindness Diagnosed?

Color vision is always subjective. There is no way to tell if you see red, blue and green with the same intensity as those people with perfect vision. During your regular eye exam, your doctor may help diagnose your condition.

The doctor may use unique patterns known as pseudoisochromatic plates when testing your color blindness.

These images feature colorful dots wherein specific images and numbers are embedded in them.

Ordinary people will be able to quickly determine the symbols and numbers while those with color blindness will not.

Parents need to know about the color visibility of their children since their early education usually involves the identification of different colors.

What Causes Color Blindness?

The retina is very sensitive to light that allows us to see colors. As we’ve mentioned, it contains cones that react to different colors.

The message will then be transmitted to our brain and will be interpreted to help us distinguish these colors.

There are various reasons why the cones in our retina will not function the way it’s supposed to. Here are some of them.


A genetic condition causes a common type of color blindness. You most probably inherited your situation from your mother.


Color blindness can also occur if you acquire an illness or traumatic injury on your retina. For instance, if you have glaucoma, the pressure can sometimes damage the optic nerve.

It can significantly diminish your capacity to distinguish different colors.

Diabetic retinopathy and macular degeneration can also cause damage to our retina. Color vision may also be affected if you have a cataract.


Some medications can trigger the changes in our color vision. Thioridazine, chlorpromazine, and other antipsychotic drugs can temporarily affect the way we see colors.

Ethambutol that is used in treating tuberculosis can cause damage to our optic nerve, which will make it difficult for us to see colors.


Ageing can also be a factor that causes color blindness. You may experience color deficiency and even vision loss as you age.

Knowing what is color blindness and what causes it will help you understand the right thing to do.

For instance, if this is caused by an injury or illness, treating the underlying cause will gradually improve your vision.

Inherited type of color blindness can be corrected with engineered color-blindness glasses.