Color blindness

Color blindness is the inability to distinguish the differences between certain colors. This condition results from an absence of color-sensitive pigment in the cone cells of the retina, the nerve layer at the back of the eye

According to the NIH, “Inherited color blindness is caused by abnormal photopigments. These color-detecting molecules are located in cone-shaped cells within the retina, called cone cells. In humans, several genes are needed for the body to make photopigments, and defects in these genes can lead to color blindness.”

Most color vision problems are inherited and are present at birth.

How common is color blindness?

Approximately 1 out of 12 males and 1 out of 20 women are color blind according to the NIH.

As many as 8 percent of men and 0.5 percent of women  have red-green color blindnes.

What allows us to see colors?

Light first enters the eye through the outer surface called the cornea.

The lens then focuses the light on the back of the eye referred to as the retina.

The retina has photoreceptors called rods and cones.

Rods detect only light and dark and are very sensitive to low light levels.

Chemical changes occur on the rods and cones when they absorb light. This allows messages to be sent to the brain.

The cones allow us to see color, they are able to decipher the different wavelengths.

The three different types of cone cells correspond to the three colors which include red, green and blue.




Color blindness can occur when one or more of the color cone cells are absent.

Why does color blindness occur?

There is a defective gene that cannot decipher some colors that are found in the cones.

Men are much more likely to be colorblind than women because genes that are responsible for the most common, inherited color blindness are on the X chromosome.

Males only have one X chromosome, while females have two X chromosomes.

Color vision depends on our eyes and brain working together to perceive different properties of light.

The color of light is determined by its wavelength.

Longer wavelength corresponds to red light and shorter wavelength corresponds to blue light.

What colors are not seen in color blindness

Red-green color blindness is the most common.

Blue-yellow color blindness is the second most common type of color blindness.

A complete absence of color vision is rare.

How does color blindness affect everyday life?

According to the website Color Blindness Awareness,

“Most red/green color blind people won’t know if they have cooked a piece of meat rare or well done and they are unlikely to be able to tell the difference between green and ripe tomatoes or between ketchup and chocolate sauce.”

Students and workforce-Reading graphs and charts that are color-coded can be difficult. This will be challenging for students or those working in businesses that require understanding graphs. Children may have a hard time learning their colors. Imagine trying to color if you do not know what red and green look like.

Food shopping and cooking-Picking ripe foods based on color and even cooking meat can be challenging.

Treatment for color blindness

There is no cure for color blindness. However, people with red-green color blindness may be able to use a special set of lenses to help them perceive colors more accurately.

Color blind glasses

Enchroma offers glasses to people who have red-green color blindness.

According to Enchroma;

“The only specialty eyewear that alleviates red-green color blindness, enhancing colors without the compromise of color accuracy.”

Don McPherson, Ph.D. is the co-founder of Enchroma. He noticed color changes when he wore protective laser eye glasses which have a coating on them.

How was Enchroma able to develop their glasses?

According to their website,

They first simulated color blindness vision.

“Enchroma utilized the latest research on the genetics of color blindness and various anomalies related to photopigments, and linked these into a model where it gives the effect on how people with red or green color blindness perceive colors.”

They then developed a filter.

“Enchroma lenses separate the overlapping red and green cones, helping improve vision for people who have difficulty seeing reds and greens.”

Apps for color blindness

Some of these apps allow color blind users to take a picture then see what color is in a certain area.

These apps can help select clothing or ripe fruits.

An example of a color blind app includes Color Blind Pal

Color blind tests

color blind testColor blind tests can help diagnose color blindness.

The most common screening test for color blindness is the Ishihara Color Vision Test. It is named after the doctor who invented the test.

Circles that are made up of smaller colored dots are used. These smaller dots make up numbers that are seen by people who are not colored blind

Are you interested in taking a  color blind test?

What do you think of color blindness?
Video credit-Casrson Stafford gives glasses to her Papa

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