Colour Blindness is a condition that many people live with day to day and like Autism, many people do not realise that they have it despite approximately 10% of the population being affected. Like Autism, colour blindness presents in varying forms from extremely mild to severe as in Extreme Deuteranopia (which the I suffer from). With ED the sufferer only perceives about 2% of the colour spectrum and to give an example, traffic lights appear as 2 yellows and a white rather than the correct red, amber and green. I can still drive safely and have had a long career in electronics, with a little allowance at times. My wife and children understand my condition and do not ask me for opinions on colour and sometimes we both laugh at situations such as the time I was told my favourite bright yellow tea mug as actually lime green.
How do I see the world? perfectly normally but not as you might see it but because I cannot see what you see, I have no way of comparing. I cannot see all the shades and subtle variations in colour that you might but, as they say, "you do not miss what you do not have".
Colour blindness, also known as colour vision deficiency, is a condition where an individual has difficulty distinguishing certain colours. While most people perceive colours normally, those with colour blindness perceive the world differently. This article explains the nature of colour blindness, its types — including deuteranopia — its impact on daily life, and support options available.
What Is Colour Blindness?
Colour blindness occurs when the photoreceptor cells in the retina — called cones — do not detect light correctly. Humans have three types of cones: red-sensitive (L-cones), green-sensitive (M-cones), and blue-sensitive (S-cones). A deficiency or absence of one or more of these cones leads to difficulties distinguishing certain colours.
Colour blindness is often inherited, though it can also result from illness, injury, or age-related degeneration. The condition is more common in males due to the X-linked inheritance pattern of many colour vision genes.
Types of Colour Blindness
Colour blindness varies depending on which cones are affected. The main types include:
- Deuteranopia (green deficiency): Individuals cannot perceive green light properly. Green may appear beige or brown, and red and green may be easily confused.
- Extreme Deuteranopia (blue & green deficiency): Individuals cannot perceive blue and green light properly. Green may appear beige, brown or red, and red and green may be totally confused. Blue, purple and similar colours all appear the same
- Protanopia (red deficiency): Red cones are absent, making red appear darker and sometimes indistinguishable from green.
- Tritanopia (blue deficiency): Blue cones are affected, causing difficulties distinguishing blue and yellow shades.
- Monochromacy: Extremely rare; one or no cone type works. Individuals see mostly shades of grey.
Deuteranopia in Detail
Deuteranopia is the most common form of red-green colour blindness, affecting roughly 1% of males and a very small percentage of females. People with deuteranopia have a missing or non-functioning green-sensitive cone (M-cone), which alters how green and some shades of red are perceived.
Typical experiences for someone with deuteranopia include:
- Difficulty distinguishing between red and green hues.
- Confusing shades of green, brown, orange, or yellow depending on lighting.
- Challenges with colour-coded tasks, such as maps, charts, or traffic lights, unless there are other cues.
“With deuteranopia, green traffic lights don’t always feel green. I rely on position and brightness instead of colour.” – A person with deuteranopia
Causes of Colour Blindness
Colour blindness can be caused by several factors:
- Genetic inheritance: The most common cause, usually passed through X-linked genes.
- Eye injuries or disease: Conditions such as glaucoma, macular degeneration, or diabetic retinopathy can affect colour perception.
- Aging: Lens yellowing over time can reduce colour sensitivity.
- Medications or chemicals: Certain drugs and chemicals can temporarily or permanently affect colour vision.
Living with Colour Blindness
Colour blindness can impact daily life in subtle or significant ways, depending on severity:
- Educational challenges: Difficulty interpreting colour-coded materials in school or work.
- Work limitations: Careers in electrical wiring, graphic design, or anything heavily reliant on colour may be challenging.
- Everyday tasks: Choosing clothing, cooking, or reading coloured maps and charts can be confusing.
Despite these challenges, many people with colour blindness develop strategies to cope, such as relying on position, labels, patterns, or brightness cues instead of colour alone.
Diagnosis
Colour blindness is diagnosed through specialised vision tests, such as:
- Ishihara plates — images made up of coloured dots that form numbers or shapes discernible only by people with normal colour vision.
- Farnsworth-Munsell 100 hue test — identifies subtle shifts in colour perception.
- Online or digital tests — helpful for preliminary screening but less precise than professional evaluation.
Support, Aids, and Treatments
There is currently no cure for inherited colour blindness, but several strategies can help manage it:
Assistive Tools
- Special lenses or glasses can enhance colour contrast for some types of colour vision deficiency.
- Apps and digital tools can help identify colours and provide alternative visual cues.
Environmental Adjustments
- Using patterns or labels instead of colour alone to convey information.
- High-contrast design in education, workplace, and public signage.
Education and Awareness
- Informing teachers, colleagues, and family about challenges helps reduce misunderstandings.
- Colour-blind-friendly design in websites, maps, and learning materials improves accessibility.
Living Successfully with Colour Blindness
Most people with colour blindness lead normal lives. Key strategies include:
- Relying on position, shape, brightness, or patterns instead of colour alone.
- Using technology to assist with colour identification.
- Adapting clothing, interior design, and daily routines to reduce reliance on colour cues.
“I don’t see colours the same way others do, but I’ve learned to interpret the world differently — and it works for me.” – A person with colour blindness
Conclusion
Colour blindness, including deuteranopia and other types, affects millions of people worldwide. While it can present challenges in education, work, and daily life, awareness, adaptive strategies, and assistive tools can make life easier. Understanding colour blindness helps society create inclusive environments where all people can thrive regardless of how they perceive colour.