Understanding Color Blindness: Challenges and Solutions

Color blindness, also known as color deficiency, is an eye condition that prevents people from seeing color. For some, it is certain colors, but some rare cases of color blindness cause people to only see in shades of black, white, and gray. Color blindness is something that many people suffer from, and it alters their whole perception of the world we all know. Read the following blog to understand and learn more about color blindness!

What is Color Blindness?

Color blindness occurs when a person is unable to see colors in a normal way. Color blindness often happens when someone cannot distinguish between certain colors. There are different degrees of color blindness some of which are more serious and have a greater impact on a person’s perception of the world. Some people with mild color deficiencies can see colors normally in good light but have difficulty in dim light. The most common kind of color blindness prevents people from seeing the colors red and green. The most severe and uncommon form of color blindness causes everything to be seen in shades of black, white, and gray. Color blindness usually affects both eyes equally and remains stable throughout life. There is general agreement that 1 in 12 men (8%) and 1 in 200 (0.5%) women are colorblind, as a result, there are more than 350 million colorblind people worldwide.

How do we Perceive Color?

Without the functions of many parts of the eye, we would not be able to perceive color, or visual images at all! Light enters through the cornea, the eye’s clear and “protective surface” which then directly leads to the pupil. The pupil can adjust its size based on the amount of light because of the iris, the colored ring of the eye that is a muscle. The light is then set on the lens, which focuses the image being viewed, which is then put onto the retina. The retina is the light sensitive inner surface of the eye with layers of neurons to convert light into neural impulses the light sensitive inner surface of the eye with layers of neurons and receptors to convert light into neural impulses. The receptors on the retina are called rods (responsible for detecting black, white, and gray as well as movement and peripheral vision) and cones (responsible for color vision). The rods and cones convert the light waves into signals which are processed by the ganglion cells. These are then processed in the visual cortex. The cones are responsible for color vision and the retina has approximately 6 million cones.

What Causes Color Blindness?

Colorblindness is mostly passed down by genetics, it is a sex-linked recessive trait resulting in it being more common in males. Most people who are color blind are born with the inability to see color. Some people lose their color vision later in life. Most color vision problems that happen later in life are a result of diseases or eye trauma. People who suffer from certain medical conditions have increased chances of becoming color blind. These medical conditions include of glaucoma, diabetes, macular degeneration, Alzheimer’s disease, Parkinson’s disease, chronic alcoholism, leukemia, and sickle cell anemia. Certain drugs may also increase the risk for acquiring color blindness.

What Happens in The Eye When Someone is Color Blind?

Color blindness occurs when cones (a type of nerve cell in the eye’s retina) aren’t working correctly. Cones process light and images as they enter the eye and send signals to the brain that allow us to perceive color. There are several types of color blindness, defined according to which types of cones aren’t working well. Cones are nerve cells in your eye that detect colors in the visible spectrum of light. This spectrum includes all the wavelengths that humans can see. These range in length from 380 nanometers (short), or nm, to 700 nanometers (long). Normally, you’re born with three types of cones:

·      Red Sensing Cones (L Cones)- These cones perceive long wavelengths (around 560 nanometers) and detect the color red. About 60% of the cones in the retina are red sensing cones.

·      Green Sensing Cones (M cones)- These cones perceive middle wavelengths (around 530 nanometers) and detect green. About 30% of the cones in the retina are green sensing cones.

·      Blue Sensing Cones (S cones)- These cones perceive short wavelengths (around 420 nanometers) and detect blue. About 10% of the cones in the retina are blue sensing cones.

Most people have all three types of cones, and these work as they should. However, if someone has color vision deficiency, at least one type of cone isn’t working properly. Problems with cones affect the ability to see colors in the traditional way. The following section elaborates on how problems with certain cones can impact how color is seen.

Types of Color Blindness

There are 7 main kinds of color blindness that people suffer from. Each kind has its own way of impacting someone’s vision and perception of the world.

·      Deuteranomaly- Deuteranomaly does not affect all green colors, but many shades of green will appear red or have a red hue. A person with deuteranomaly has M-cones (which detect green light) that are present, but weak.

·      Deuteranopia- The M-cones are entirely missing, which makes it impossible to distinguish green colors. Instead, green appears as beige.

·      Protanomaly- This makes certain shades of red look green and causes them to appear less bright than they are. Has L-cones (responsible for long wavelengths, in this case, red light) that are red-weak. Shades of red may appear more green and less bright.

·      Protanopia- The L-cones that are missing entirely, causing them to be unable to distinguish red from green, and red colors may appear dark gray or shaded.

·      Tritanomaly- Caused by weak S cones that don’t function properly, making it hard to distinguish between blue and green or red and yellow.

·      Tritanopia- Has no S cones, makes it hard for someone to tell the difference between blue and green, purple and red, and yellow and pink.

·      Monochromatism (Monochromacy)- Makes it impossible for a person to perceive any color. A genetic abnormality that also impacts the ability to see clearly. This type of vision impairment is incredibly rare.

Daily Color-Blind Struggles and Dangers

Color blindness can be a struggle for the people who suffer with it. Daily tasks like picking out clothes, driving, playing sports, and even eating can create difficulties for an individual. The most dangerous task is driving, especially because red-green deficiency is the most common kind of color blindness. Studies show that color deficient drivers have self-reported difficulties on the road such as distinguishing traffic signals, confusing traffic lights with streetlights, and detecting brake lights. Certain expressions and social cues are shown by colors, several physiological studies have demonstrated that human facial color also varies with emotional states. The results of one experiment show that reddish-colored faces enhance anger perception and bluish-colored faces enhance sadness perception. Having color blindness can be both inconvenient and dangerous at times, it is important to be aware of this condition that many people struggle with. However, many people with color blindness don't know to look for these differences because they've always seen colors in the same way. So, they don't realize anything's different about their color vision. Most people find out when they take a test!

This is a traditional color blind test

Color Blind Solutions

Unfortunately, there are no known cures for color blindness. However, with new advances in medical based technology, color blind glasses and contact lenses can be used to enhance certain colors.

Normal Vision Monochromacy

Citations:

Pair Eyewear. “Customizable Glasses and Sunglasses.” Pair Eyewear, 9 Aug. 2024, https://paireyewear.com/blogs/news/types-of-color-blindness

Turbert, David. “What Is Color Blindness?” Edited by Alejandra G de Alba-Campomanes, American Academy of Ophthalmology, 10 Sept. 2024, https://www.aao.org/eye-health/diseases/what-is-color-blindness

“Cones.” American Academy of Ophthalmology, 19 Dec. 2018, https://www.aao.org/eye-health/anatomy/cones#:~:text=Cones%20are%20a%20type%20of,help%20us%20see%20fine%20details.

“Color Blindness: Types, Causes & Treatment.” Cleveland Clinic, https://my.clevelandclinic.org/health/diseases/11604-color-blindness

Nakajima, Kae, et al. “Interaction between Facial Expression and Color.” Nature News, Nature Publishing Group, 24 Jan. 2017, https://www.nature.com/articles/srep41019#:~:text=These%20results%20show%20that%20reddish,reddish%2Dcolored%20face%20appears%20angrier.