What is Colour Blindness?

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Colour. It affects every part of our lives. Colour is emotional, experiential, and tactical. It gives art life. It entices us to eat certain foods and buy certain jewelry, and sometimes it literally defines these things. We also use colour to interpret information such as signs and lights. It is deeply ingrained in our basic perception of the world. When the ability to see colour is deficient, as in the case of colour blindness, there is a dulling of what is seen; or one might say there is a dulling effect in how we see.

Definition of Colour Blindness

What is colour blindness? Colour blindness is a reduced ability to distinguish between colours when compared to the standard for normal human colour vision. When a person is colour blind, also called colour vision deficiency (CVD), they usually have difficulty distinguishing between certain colours such as yellow and orange, green and brown, pink and gray, or blue and purple. These confusions are typical of what is called “red-green colour blindness,” which includes protan-type CVD (protanomaly and protanopia) and deutan-type CVD (deuteranomaly and deuteranopia).

Red-green colour blindness is usually inherited via X-linked recessive genes. Other types of colour blindness exist also, such as tritan-type CVD, also called blue-yellow colour blindness, which is associated with the inability to see shades of blue, and confusions between blue and green colours. Blue-yellow colour blindness is usually caused by age-related eye conditions such as glaucoma, or exposure to certain chemicals or medical treatments. In very rare cases, a person can be completely colour blind, meaning they see only the intensity of light, but not its colour. This is called monochromacy or achromatopsia. Achromatopsia can be inherited but can also result from progressive eye diseases such as retinitis pigmentosa. In summary, there are many types and degrees of what can be considered “colour blindness,” ranging from partial to complete lack of colour discrimination.

To learn if you are colour blind, take the EnChroma Colour Blind Test. If you have colour blindness, our test can tell you your type of colour vision and if your colour vision deficiency is mild, moderate, or strong — in less than two minutes.

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Fun Facts About Colour Blindness

The world of colour vision is full of intricacies and interesting facts. At EnChroma, we want you to know everything there is to know about being colour blind. So here’s a list of some of the most fun facts we know about colour blindness.

#1 Babies Are Born Colour Blind

As babies grow, their colour vision improves and is typically fully developed by the age of 6 months. Overall colour discrimination capability reaches its peak by age 20, and then starts to decline again.

#2 Dogs Don't See In Black And White

Dogs & Colour Blindness: Contrary to popular belief, dogs don’t actually see in black and white. Dogs are dichromates, which means they have two types of cone cells, and see in mostly blue and yellow. Their vision is somewhat similar to that of a person with protanopia.

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Fun Facts About Colour Blindness

#3 Peanut Butter Isn't Green

People who are red-green colour blind are often surprised to find out that peanut butter is NOT green! Green and brown is a common colour confusion that seems to be particularly relevant to the shade of peanut butter. Also, because colour blind people have a hard time distinguishing between green and yellow, they often have a hard time knowing when a banana is ripe. Many are accustomed to the bitter taste of an unripe banana!

#4 Rainbows May Appear to Have 2-3 Colours

To the normally sighted person, a rainbow features all the colours of the rainbow. For many colour blind people, however, a rainbow only appears to have 2 bands of colour: blue and yellow. This can also make the green light on a stoplight may appear white or even blue, while the red and yellow lights may look similar to each other.

Testing For Colour Blindness

If you or a family member are having problems recognizing or distinguishing between colouurs that other people seem to see, it’s easy enough to determine whether you are colour blind without visiting a doctor. The EnChroma Colour Blind Test is an online colour blind test designed to estimate the type and level of colour blindness. Created by EnChroma, an independent company based in California, the EnChroma colour blind test is the #1 online colour blind tool for colour vision deficiency that has so far been taken by more than one million people worldwide.

The EnChroma test is based on the classic and widely-used Ishihara “hidden digit” test method and is combined with a computer-adaptive algorithm to measure the type and level of colour vision deficiency (CVD). It is available in a numbers mode for adults and children ages 10+ and in a shape mode for kids ages 5+.

The Ishihara test for colour blindness is named after a Japanese ophthalmologist Shinobu Ishihara who invented the test for the Japanese army in 1917. Ishihara has been a good screening test, but it is 100 years old and does not leverage the benefits of today’s computer-based adaptive testing protocols. The EnChroma test deters memorization and cheating and can be self-administered on a phone or laptop.

Testing children for colour blindness poses unique challenges. Colour vision develops early in infancy, but until a child can name colours or numbers it is challenging for a parent, teacher or eye care professional (ECP) to learn if a child is colour vision deficient (CVD). As a result, many children with colour blindness go undiagnosed. To solve this problem, EnChroma introduced in 2019 a Kids Colour Blindness Test that enables younger children to take the test in “shape mode,” in which identifying simple geometric shapes (square, circle, triangle) replace the standard numeric symbols.



Who Should Take a Colour Blind Test?

Since the EnChroma Colour Blind Test is easy, quick and free, it’s really something that anyone can do to satisfy their curiosity about their colour vision. In some cases, colour vision deficiency can be very mild and may not be noticed until it becomes a problem, such as when applying for a job that requires a high degree of colour discrimination. Anyone with a family history of colour blindness should consider taking the test. For certain professions where colour perception is an important factor, including electricians, pilots, designers, and artists to name a few – a colour blind test can identify potential issues that might crop up in the course of employment.

Testing For Colour Blindness

If you or a family member are having problems recognizing or distinguishing between colouurs that other people seem to see, it’s easy enough to determine whether you are colour blind without visiting a doctor. The EnChroma Colour Blind Test is an online colour blind test designed to estimate the type and level of colour blindness. Created by EnChroma, an independent company based in California, the EnChroma colour blind test is the #1 online colour blind tool for colour vision deficiency that has so far been taken by more than one million people worldwide.

The EnChroma test is based on the classic and widely-used Ishihara “hidden digit” test method and is combined with a computer-adaptive algorithm to measure the type and level of colour vision deficiency (CVD). It is available in a numbers mode for adults and children ages 10+ and in a shape mode for kids ages 5+.

The Ishihara test for colour blindness is named after a Japanese ophthalmologist Shinobu Ishihara who invented the test for the Japanese army in 1917. Ishihara has been a good screening test, but it is 100 years old and does not leverage the benefits of today’s computer-based adaptive testing protocols. The EnChroma test deters memorization and cheating and can be self-administered on a phone or laptop.

Testing children for colour blindness poses unique challenges. Colour vision develops early in infancy, but until a child can name colours or numbers it is challenging for a parent, teacher or eye care professional (ECP) to learn if a child is colour vision deficient (CVD). As a result, many children with colour blindness go undiagnosed. To solve this problem, EnChroma introduced in 2019 a Kids Colour Blindness Test that enables younger children to take the test in “shape mode,” in which identifying simple geometric shapes (square, circle, triangle) replace the standard numeric symbols.



Who Should Take a Colour Blind Test?

Since the EnChroma Colour Blind Test is easy, quick and free, it’s really something that anyone can do to satisfy their curiosity about their colour vision. In some cases, colour vision deficiency can be very mild and may not be noticed until it becomes a problem, such as when applying for a job that requires a high degree of colour discrimination. Anyone with a family history of colour blindness should consider taking the test. For certain professions where colour perception is an important factor, including electricians, pilots, designers, and artists to name a few – a colour blind test can identify potential issues that might crop up in the course of employment.