Colour Vision and Colour Vision Deficiency

Colour Vision and Colour Vision Deficiency

“It's not just what we see, it's how we see it!”
Exploring the world of colour vision, and colour vision deficiency

Colour-correcting lenses, like COLORON glasses, filter specific wavelengths of light to enhance colour discrimination. This method can effectively improve colour discrimination and, in the long term, colour identification. You quickly get used to the seemingly uniform hue you experience in the short term (10-15 minutes) and the world becomes more colourful than ever.

Currently, there is no cure for Colour Vision Deficiency (CVD). While there are tools and aids to assist individuals with CVD, they don't "cure" the condition but can help with colour perception.

Colour Vision Deficiency (CVD), commonly known as colour blindness, is a condition that affects millions of people worldwide. Before delving into potential cures or treatments, it's crucial to understand the nature of CVD and how it impacts individuals.

CVD is relatively common, affecting around 8% of men and 0.5% of women of Northern European ancestry. It varies in prevalence across different populations.

Understanding the prevalence of Colour Vision Deficiency (CVD) is essential to appreciate the scope of this condition. It affects a significant portion of the population, with varying degrees of severity.

Symptoms of CVD include difficulty distinguishing between specific colours, frequently confusing colours like red and green, and unusual colour choices in drawings or art.

Recognising the symptoms of Colour Vision Deficiency (CVD) is the first step in identifying and addressing this condition in children. Let's explore the signs that parents and educators should be aware of.

Colour vision deficiency is diagnosed through colour vision tests, such as the Ishihara test or the Farnsworth-Munsell 100 Hue Test, administered by eye specialists or pediatricians.

Diagnosing Colour Vision Deficiency (CVD) is a crucial process to ensure that individuals receive the support they need. Understanding the diagnostic methods and the importance of early detection is key.

Colour vision deficiency is primarily caused by genetic factors and is inherited from parents. In some cases, it can be acquired due to medical conditions or medications.

The origins of Colour Vision Deficiency (CVD) are rooted in genetics, but there are also acquired forms of the condition. Let's delve into the causes and contributing factors.

Individuals with colour vision deficiency may face challenges in distinguishing colours in daily life. Coping mechanisms include using texture and shape cues, using colour-enhancing tools, and developing adaptive strategies.

Colour Vision Deficiency (CVD) can present daily challenges for children, but with the right strategies and support, they can thrive. Explore how parents, educators, and caregivers can help children cope.

Individuals with colour vision deficiency see the world with altered colour perception. They may have difficulty distinguishing certain colours or perceive them differently than those with normal colour vision.

Understanding the unique way individuals with Colour Vision Deficiency (CVD) perceive colours is both fascinating and enlightening. Gain insights into their world and gain a deeper appreciation for their experiences.

The higher prevalence of colour vision deficiency in men can be attributed to genetics. The genes responsible for colour vision are located on the X chromosome. Men have only one X chromosome, while women have two.

What is colour?
What is colour?

Colour is the visual perception that arises when different wavelengths of light interact with our eyes and brain, causing us to perceive a range of different colours and tones.


IN PHYSICS


Colour corresponds to electromagnetic radiation of specific wavelengths within the visible spectrum, which ranges approximately from 380 nm to 780 nm.

IN PHYSIOLOGY


Colour is the result of differential stimulation of the photoreceptors in the eye (cones) by various wavelengths of light. This stimulation is first converted into receptor potentials and then into neural signals that our brain can interpret.


IN PSYCHOLOGY


Colour is a subjective experience or sensation created in the brain's cortical visual centres in response to stimuli from the visual system. This sensation, known as colour perception, can be influenced by various factors including context, memory, and individual differences – and enables us to name colours.

Light interaction with objects
Light interaction with objects

When light contacts an object, the object can absorb, reflect or transmit the light.

This is determined by the arrangement of electrons in the atoms, which, according to quantum laws, absorb photons of certain energies (wavelengths) - and reflect others.

The actual "colour" of an object is therefore the wavelengths of light that it reflects into the eye.


That's cool, isn't it? But it gets even more interesting...


Different light sources, such as sunlight, incandescent bulbs or LEDs, can shift colour appearances to various degrees depending on their colour temperatures.

Why colour matters

Colour is more than just a visual sensation; it plays a crucial role in our lives.

Besides allowing us to connect and appreciate our surroundings, it lets us perform tasks, hobbies and activities with greater confidence.


It is the functional aspects of colour vision which simplify our daily activities and the decision we make during everyday moments.


Although it varies from one person to the next, colour deficient individuals may face challenges in various aspects of their daily lives.

Interpreting colour-coded information in textbooks, graphs, and diagrams. Distinguishing between colours used for highlighting or organising information.

Potential misinterpretation of colour-based educational materials, such as maps and charts.

Career options in fields that require accurate colour discrimination, such as graphic design, fashion design, and certain scientific research roles.

Challenges in jobs where colour coding is essential, such as electrical wiring or safety instructions that rely on specific colour indications.

Recognising important signals or warning signs that are colour-coded, like traffic lights, road signs, and alerts in industrial settings.

Issues with colour-coordinated tasks, such as cooking (estimating food doneness), sorting laundry, and matching clothes.

Challenges in selecting ripe fruits or vegetables based on colour cues.

Difficulty appreciating and creating art that relies heavily on colour variations.

Limited ability to differentiate subtle nuances in colour shades, which may impact artistic expression.

Potential misunderstandings related to clothing choices, as well as challenges in coordinating outfits.

Difficulty participating in colour-based games or activities that others enjoy.

Challenges in identifying changes in the environment, such as the changing colours of leaves in different seasons.

Potential frustration, especially when trying to explain the condition to others who do not understand colour vision deficiency.

Feelings of exclusion or being different from the others.

How light enters the eye
How light enters the eye

Incoming light shines through our eyes and interacts with specialised cells at the back of our eyes called cones.

We have three distinct types of cones:

1. Protos (red-sensitive cone cells)

2. Deuteros (green-sensitive cone cells)

3. Tritos (blue-sensitive cone cells)

Together, these three types of cones enable us to experience the full spectrum of colour in our world.

Cone sensitivity shifts and signal overlaps
Cone sensitivity shifts and signal overlaps

The normal state of colour vision that most people experience is called trichromacy. Here individuals possess three types of functioning cone cells.


When the sensitivity range of a cone type is shifted away from the normal range, the signal inputs to the brain start to overlap, causing a "confusion potential".


Depending on which cone type is not functioning properly and depending on the severity of this, we distinguish between types of colour vision deficiencies, partial colour blindness and actual colour blindness.

DEUTAN / GREEN WEAKNESS
DEUTAN / GREEN WEAKNESS
COLOUR VISION DEFICIENCY TYPES

Deuteranomaly

In this case the green-sensitive cones (Deuteros) deviate from the normal (anomaly) and result in an alteration in the perception of red and green colours. The size of the overlap between these signals determines the severity of the colour vision impairment.

This condition falls under the category of red-green colour deficiency.


Deuteranopia

In this case the near-to absence of green-sensitive cones (Deuteros) results in an inability to process green signals.

This condition falls under the category of partial red-green colour blindness.

PROTAN / RED WEAKNESS
PROTAN / RED WEAKNESS
COLOUR VISION DEFICIENCY TYPES

Protanomaly

In this case the red-sensitive cones (Protos) deviate from the normal (anomaly) and result in an alteration in the perception of red and green colours. The size of the overlap between these signals determines the severity of the colour vision impairment.

This condition falls under the category of red-green colour deficiency.


Protanopia

In this case the near-to absence of red-sensitive cones (Protos) results in an inability to process red signals.

This condition falls under the category of partial red-green colour blindness.

TRITAN / BLUE WEAKNESS
TRITAN / BLUE WEAKNESS
COLOUR VISION DEFICIENCY TYPES

Tritanomaly

In this case the blue-sensitive cones (Tritos) deviate from the normal (anomaly) and result in an alteration in the perception of blue colours. The size of the overlap between these signals determines the severity of the colour vision impairment.


Tritanopia

In this case the near-to absence of blue-sensitive cones (Tritos) results in an inability to process red signals.

This condition falls under the category of partial red-green colour blindness.

COLORON technology can not help these individuals as of today.

COLOUR BLINDNESS
COLOUR BLINDNESS

Blue cone monochromacy, along with achromatopsia are conditions where affected individuals will perceive almost no colour or no colour at all. This is the most severe form of colour blindness.

COLORON technology can not help these individuals as of today.

How common is it?
How common is it?

It is estimated that 1 in every 12 man and 1 in every 200 woman has a form of colour vision impairment.


This means that in every second family of 20 people there is a colour deficient person.


There is a colour deficient child sitting in every third classroom.

What causes colour vision deficiency and colour blindness

Although colour vision deficiency and colour blindness can result from eye pathologies or accidents, the most common form of CVD is congenital, meaning that it is present from birth.


Inherited abnormalities in cone cells are largely associated with the X chromosome. This chromosomal connection leads to males, who possess XY sex chromosomes.


In males, if a gene responsible for a particular type of cone cell is flawed on the X chromosome, there is no compensatory counterpart on the Y chromosome.


In contrast, females, with XX chromosomes, can carry a functional gene copy even if one is flawed. This is why females often serve as carriers of this genetic information without expressing the deficiency themselves.

The genetic asymmetry in males (XY) predisposes them to express colour vision deficiency. This inherent difference between male and female genetics underscores the prevalence of CVD among males.