Although not a form of blindness, ‘color blindness’ is a form of deficiency in the way people see color. While most people share a common color vision sensory experience, some may experience colors differently known as Color Vision Deficiency (CVD).
Severe forms of these deficiencies are categorized as color blindness and people living with it aren’t aware of differences between colors that may seem obvious for most.
1. TYPES OF COLOR BLINDNESS
A person with normal color vision can typically perceive up to 1 million different shades of colors. Normal color-sighted individuals are Trichromats, meaning they have three different color sensitive cones in their retina: red, green, and blue. Each of these red, green, and blue cones are sensitive to different wavelengths of light and help to create color perception. The unique separation and overlap work together to enable those with normal color vision to see all the colors of the spectrum.[i]
The red, green, and blue color sensitive cones of a person born with color vision deficiency are positioned in such a way that there is less separation between them and an excessive overlap. This reduces the shades of colors seen and the brightness of color, compromising the perception of many colors. As a result, it is believed that a person with typical red-green color blindness often perceive only 10% as many shades of color as a person with normal color vision.[ii]
3 Main Types of Color Vision
Deficiency:
Protan Color Blindness:
Protanomaly is referred to as “red-weakness”, an apt description of this form of color deficiency. Any redness seen in a color by a normal observer can be harder to see by the protanomalous viewer. [iii]
Deutan Color Blindness:
The deuteranomalous person is considered “green weak”. Similar to the protanomalous person, they have difficulty discriminating small differences in hues in the red, orange, yellow, green region of the spectrum.[iv]
Tritan Color Blindness:
Tritanomaly, causing reduced blue sensitivity and Tritanopia, resulting in no blue sensitivity, can be inherited or acquired; the inherited form is a rare autosomal recessive condition. [v]
2. PRIMARY SIGNS OF COLOR BLINDNESS

Many people who have a form of color blindness may not even realize it until it is pointed out to them. Color blindness comes in varying degrees and most people who are considered to be color blind can still see colors, but certain colors appear washed out and can easily be confused or blended with other colors. Color blindness is most commonly hereditary and affects mostly males. As a matter of fact, many forms of Color Vision Deficiency affect approximately 1 in 12 men (8%) and only 1 in 200 (0.5%) women, however, more women than men are carriers of color blindness, even though they are not colorblind themselves.
3. HOW TO ASSIST PATIENTS WITH COLOR BLINDNESS
As with any other deficiency, some people with color blindness may have feelings of frustration or anger towards their inability to see certain colors. It’s important to remind them that it may take some time, but they will be able to adapt to their color vision deficiency.
For younger patients, especially those in primary or secondary school, it’s important to foster an inclusive environment at their schools. Remind their parents to speak with the schools and teachers so they can prepare lessons and presentations to accommodate the student’s color deficiency. The child will be able to follow along easily in class without feelings of being left out or confused.
Remind patients that there are options for them if they wish to see colors better. There are contact lenses and optical lenses on the market that could help with their color vision deficiency or apps to download on their phones that help them distinguish colors. The more your patients know about the options out there, the more at ease they’ll feel. For patients who may believe they have a form of Color Vision Deficiency, direct them to this online test they can take to see if they are indeed color blind.
4. MAKING YOUR PRACTICE MORE ACCESSIBLE
For patients who come to your practice and have trouble navigating the area or accessing certain services due to their color blindness, there are ways to make the clinic a bit more accessible and welcoming for patients who require it. Here are some simple steps you can take to make your office more accessible to people with Color Vision Deficiency:
- Writing in black on a white background instead of using colors.
- Making copies of handouts with a high black/white contrast, and not on colored paper
- When possible, writing out the names of colors if they are relevant to instruction (green pen, red frames, etc.)
- Using detailed explanations to describe frame details (for example: maroon red rather than simply red)
Ways to help patients with color blindness:

[i] https://enchroma.com/pages/normal-color-vision-test-result
[ii] https://enchroma.com/pages/normal-color-vision-test-result
[iii] http://www.colorvisiontesting.com/color2.htm
[IV] http://www.colorvisiontesting.com/color2.htm
[V] https://enchroma.com/pages/types-of-color-blindness