What Do Color-Blind People See?

Color blindness, also known as color vision deficiency, is a condition where someone cannot see colors normally in both eyes. It represents a group of conditions that affect color perception, including red-green color blindness, blue-yellow color blindness, and blue cone monochromacy. Red-green color vision defects, the most common form of color vision deficiency, occurs in about one in 12 males and one in 200 females among people of Northern European ancestry.

Definition

The retina in your eye is in charge of detecting color. The retina is made up of two photoreceptor cells known as rods and cones. While rods detect brightness and darkness, cones detect color. There are three types of color cone cells: red, green, and blue. The brain uses input from these cone cells to determine our color perception.

Color blindness occurs when one or more of the color cone cells are absent, not working, or detect a different color than normal. When the one or all color cone cells are not present, mild or severe color blindness takes place.

Color blindness also vary by severity. Severe color blindness occurs when all three cone cells are absent. Mild color blindness happens when all three cone cells are present but one cone cell does not work right. Some people with mild color vision deficiency can see colors normally in good light, but have difficulty in dim light. Others cannot distinguish certain colors in any light. The most severe form of color blindness, in which everything is seen in shades of gray, is uncommon. Color blindness usually affects both eyes equally and remains stable throughout life.

People are usually born with color blindness, but some can also become color-blind later in life. Color blindness can happen if your eyes or the part of your brain that helps you see color is damaged. This can be caused by:

• Eye diseases, like glaucoma or macular degeneration
• Brain and nervous system diseases, like Alzheimer’s or multiple sclerosis
• Some medicines, like Plaquenil, which is a rheumatoid arthritis medicine
• Eye or brain injuries

Color vision may also decline in the aging process, especially with cataracts, cloudy areas on the eye. These cases are called acquired color vision deficiencies.

Types of Color Blindness

There are different types of color blindness, and each type affects the way you see color. Each cone contains a specific pigment (a photopigment called an opsin) that is most sensitive to particular wavelengths of light. The brain combines input from all three types of cones to produce normal color vision. Mutations in the genes that provide instructions for making the three opsin pigments in cones cause different forms of color blindness.

Red-Green Color Blindness

The most common type of color blindness is red-green color blindness. In this condition, it is very difficult to distinguish between red and green. 

Cones with opsin made from the OPN1LW gene are called long-wavelength-sensitive or L cones, while those with opsin made from the OPN1MW gene are called middle-wavelength-sensitive or M cones and cones with opsin made from the OPN1SW gene are called short-wavelength-sensitive or S cones.

Genetic changes involving the OPN1LW or OPN1MW gene cause red-green color blindness through an absence of L or M cones or to production of abnormal opsin pigments in these cones that affect red-green color vision. 

There are four types of red-green color blindness:

• Deuteranomaly happens when the M cones of the eye are present but non-functional. It causes green colors to look red
• Protanomaly occurs when the L cones of the eye are present but non-functional. It causes red colors to look green
• Protanopia occurs when the L cones of the eye are not present. It does not allow you to perceive red light
• Deuteranopia happens when M cones of the eye are not present. It does not allow for perception of green light

Blue-Yellow Color Blindness

The less common type of color blindness is the blue-yellow color blindness, also known as tritan defects. It affects men and women equally. Blue-yellow color blindness affects 1 in 10,000 people worldwide. This condition makes it difficult to tell the difference between the colors blue and green, yellow and red, and dark blue and black.

There are two types of blue-yellow color blindness:

• Tritanomaly makes it difficult to differentiate between blue and green, and between yellow and red
• Tritanopia disables you from telling the difference between blue and green, purple and red, and yellow and pink. It makes colors look less bright too

Red-green and blue-yellow color blindness disrupt color perception, but do not affect visual acuity.

Blue Cone Monochromacy

This type is uncommon and more severe because you won’t be able to see any shade of color at all. People with this kind of color blindness have additional vision problems such as increased light sensitivity (photophobia), involuntary eye movements (nystagmus), and nearsightedness (myopia). Blue cone monochromacy is sometimes considered to be a form of achromatopsia, a disorder characterized by a partial or total lack of color vision with other vision problems.

Blue monochromacy affects about one in 100,000 people worldwide and occur at a higher rate in males than in females.

What Color Blind People See

What color blind people see differs depending on the type and extent of color blindness. People with red-green color blindness naturally have more color vision than those who have blue-yellow or complete color blindness.

Normal Color Vision vs. Protanopia

People who have protanopia are red-blind and see more green than red. They find it hard to tell between red-related colors.

Normal Color Vision vs. Deuteranopia

People who have deuteranopia see more of red than green. They have difficulty telling the difference between green-related colors.

Normal Color Vision vs. Blue-Yellow Color Blindness

People who have tritanopia are blue-blind. They have difficulty in telling the difference between blue-related colors.

Normal Color Vision vs. Blue Cone Monochromacy

People who have blue cone monochromacy don't see colors at all. They see everything in black and white.

How to Adjust

Living with color blindness can be hard, especially when performing daily tasks that require you to differentiate colors such as watching the traffic light. Examples of some daily activities that affect color blind people are: 

• Driving
• Dressing up
• Making meals
• Using gadgets

Nevertheless, it is possible to live normally with color blindness by changing some daily routines, including:

• Memorizing daily activities. Activities like driving can become tough, especially when you get to stoplights. You can memorize the position of the light to tell you what to do when the color changes position
• Altering the lighting at your home or office. Your eyes can’t detect color in the dark, so working in a dark or poorly lighted home makes it harder to see with color blindness. Try using daylight bulbs to brighten your home or office
• Labelling your clothes. Dressing up daily can be a chore if you’re color blind and that's why it’s important you adopt the labelling system. Using color labels can assist you to complete more daily activities in a shorter time. 
• Using your other four senses. We have five senses, and sight is only one of them. We still have the sense of smell, touch, taste, and hearing. Making meals in the kitchen is easier by relying on your other senses. Also, choosing fresh fruits from the grocery store can be done using your sense of smell and touch
• Enabling the accessibility button on your phone. A lot of modern gadgets have an accessibility option that people with disabilities can use on their phones. Enabling this option on your TV or phone can increase the ease in using them. Downloading apps that are built for color blind people can also help

EnChroma Glasses can help bring back partial color acuity for some color blind people. If you have color blindness, discuss with your physician ways you can manage color blindness.

A Word From Verywell

Living with color blindness can be difficult, but it isn’t impossible. There are many ways to adjust and cope with it. By tweaking your daily routine and using the right tools, you can live normally and prevent color blindness from disrupting your daily life. .