A rapid numbers test accessible on your smartphone can provide an initial indication of whether you might be colour blind, a condition impacting millions of people worldwide. While this digital check offers convenience for the curious or concerned, the National Health Service strongly recommends that anyone with suspicions about their colour vision should seek a professional assessment from an optician promptly for an accurate diagnosis.
Understanding Colour Blindness Prevalence and Types
Colour blindness, or colour vision deficiency, is a relatively common condition. Statistics reveal it affects approximately one in twelve men, equating to about 8% of the male population, and one in two hundred women. In the United Kingdom alone, there are an estimated three million individuals living with colour blindness, representing roughly 4.5% of the total population, with a significant majority being male.
Globally, the numbers are even more substantial, with Colour Blind Awareness estimating around 300 million people worldwide have some form of colour vision deficiency. The organisation clarifies that there are several distinct types of colour blindness. In exceedingly rare instances, individuals may be unable to perceive any colour at all, a condition known as achromatopsia. However, the vast majority of colour blind people experience difficulty in fully distinguishing red, green, or blue light.
The Most Common Form: Red/Green Colour Blindness
The most prevalent forms are collectively termed 'red/green colour blindness'. It is crucial to understand that this is an umbrella term encompassing various types and degrees of severity. For someone with this deficiency, colours containing elements of red or green can be easily confused.
For example, a person with red/green colour blindness might struggle to differentiate between blue and purple because they cannot properly perceive the red component within the colour purple. This can lead to daily challenges and misunderstandings.
Why Diagnosis Matters: Career and Well-being
Some may question the importance of obtaining a formal diagnosis for colour blindness. Colour Blind Awareness emphasises that the condition can significantly influence career choices, as certain professions like piloting, electrical engineering, or graphic design require accurate colour perception. Furthermore, it can be a source of frustration in everyday life, affecting tasks from choosing clothing to interpreting data charts.
Early diagnosis, particularly in childhood, is vital. Undiagnosed colour vision deficiency can impact a child's educational experience, self-esteem, and overall well-being, potentially leading to difficulties in colour-related learning activities.
The Viral At-Home Test and How It Works
The recent trend involves a simple test popularised on social media platforms like TikTok. A user, @eyedr.ang, demonstrated the traditional Ishihara's Tests for Colour Deficiency book, used by professionals, as a makeshift at-home assessment. The test involves viewing pages filled with circles composed of coloured dots.
Each circle contains a number formed by dots of a slightly different colour set against a contrasting background. When viewed on a smartphone or laptop screen, individuals with normal colour vision should readily identify the number. However, if you find it challenging to distinguish the number from the background—for instance, struggling to see red numbers against a green backdrop—it may suggest a red/green colour deficiency.
As the TikToker explained, getting any of the numbers incorrect typically indicates a potential red/green colour vision issue. The video sparked widespread engagement, with many commenters reporting they got several answers wrong, and some even missed all of them, highlighting how common undetected colour blindness might be.
Official NHS Guidance on Symptoms and Testing
According to the NHS, the primary symptom of colour vision deficiency is difficulty distinguishing between certain colours. This condition can be present from birth or develop later in life at any age.
For parents, detecting colour blindness in children can be subtle. You might observe your child:
- Using unusual colours in artwork, such as drawing purple leaves on trees.
- Experiencing challenges with tasks that involve sorting or matching colours.
- Showing a lack of interest in colouring activities.
- Relying on other senses, like smell, before eating food.
The NHS advises visiting an optician if you or your child exhibits any signs of colour vision deficiency. There are two main professional tests used for diagnosis:
- The Ishihara Test: This involves reading numbers or patterns embedded within images made of coloured dots, similar to the viral online version.
- Colour Arrangement Tests: These require organising coloured objects or caps in a precise order based on their hue and shade.
It is important to note that colour vision testing is not a standard component of the routine NHS eye examination. Therefore, you must specifically request it from your optician if you have concerns. While online tests are readily available and can be a useful preliminary step, the NHS underscores that they are no substitute for a comprehensive evaluation by a qualified eye care professional. A proper diagnosis ensures accurate understanding, appropriate advice, and support for managing the condition effectively in daily life.
