Why visual contrast is essential for dementia-friendly documents.
Recently I spent a couple of days away with my husband Mark. We stayed in a lovely apartment that we accessed from a communal stairwell. As we walked past the lift, Mark suddenly hesitated, for a split second, before moving on. Why? On the pale grey floor was a dark-coloured mat.
If I mention that Mark is living with Alzheimer’s disease, you might have a clue about the hesitation. For that short moment, his brain was perceiving the mat as a hole in the floor and, understandably, telling him to stop. His depth perception wasn’t functioning in the ‘normal’ way.
A different, but related, incident happened a few days ago. We were laying slate in the garden. As Mark spread the slate chippings, he put his white patterned scissors down onto the dusty slate chippings. Immediately they became invisible to him and he lost them. The changes in his brain have affected his contrast sensitivity and he sometimes finds it tricky to distinguish between similar coloured items placed together.
If someone mentions dementia, we often think immediately of memory problems. But visual challenges like these are also very common symptoms and worth remembering when we’re producing written information. Because if our readers living with dementia experience visual challenges, then the documents we produce become harder to process.
How dementia affects visual processing
Our vision is a sophisticated neurological process and it includes far more than the physical capabilities of the eyes. Our eyes capture light and transmit initial signals but the real act of “seeing” happens in the brain. That’s where the raw visual data is interpreted, processed, and given meaning.
This means that damage to specific brain regions can profoundly alter how we perceive and understand the world around us. Someone living with dementia might have perfect vision but still struggle to make sense of what they see.
Brain regions involved in visual processing
Certain specific brain regions are key to visual processing:
The occipital lobes, located at the very back of the brain, are our primary visual processing centres. If these areas are damaged, the brain can find it difficult to correctly interpret message from the eyes. For example, someone might mistake a shadow for an object or a pattern on the floor for a hole.
The temporal and parietal lobes also play a crucial part in our visual processing, including object and face recognition. They help us to judge distances and contribute to our spatial awareness. If these lobes are damaged, people can experience visuospatial difficulties. They might find it difficult to recognize familiar faces (known as ‘prosopagnosia’) or familiar objects (‘visual agnosia’). They might also find it hard to judge distances correctly.
Visual challenges in different types of dementia
It’s important to remember that ‘dementia’ is an umbrella term that covers many different conditions. Every individual living with dementia has a different experience. The specific visual challenges that someone might face can vary depending on the type of dementia they have. Here are three examples:
Alzheimer’s Disease: Again, when we hear the term Alzheimer’s Disease, we often think immediately of memory loss. But, Alzheimer’s Disease can also often cause difficulties with visual perception. These can include blurred vision, slower adjustment to changes in light, reduced peripheral vision, and difficulty processing distance and three-dimensional objects. People living with Alzheimer’s Disease can sometimes find it harder to recognize objects or have problems with eye movement control.
Vascular Dementia: Vascular Dementia is caused by damage to brain blood vessels. It can cause double vision, loss of part of the visual field, and involuntary eye movements, amongst other visual challenges.
Posterior Cortical Atrophy: This is a rarer form of dementia that primarily affects the brain’s visual processing centres. People living with Posterior Cortical Atrophy often find tasks relying on vision very difficult. This can include reading, identifying objects, recognizing faces, and understanding numbers.
With just those three examples, we can see that people living with dementia can face a wide variety of visual challenges. Understanding this can help us tailor our documents better.
2. Depth perception and contrast sensitivity
As we’ve seen, dementia can affect two vital visual abilities: depth perception and contrast sensitivity.
Depth perception is our ability to judge distances between objects and perceive the world in 3D. When our depth perception is affected, a room can appear “flat”. This means that everyday tasks that rely on spatial judgement become harder, such as walking up and down stairs or reaching for a coffee cup. Using features like drop shadows in our written information can further increase cognitive load.
Contrast sensitivity is our ability to distinguish between subtle differences in brightness and colour between an object and its background. People living with dementia often experience reduced contrast sensitivity. Text or objects can blend into their background making them incredibly hard to see. So, for example, light blue text on a white background becomes almost invisible, even if someone generally has good vision.
3. Why contrast matters
When our documents, graphics, brochures, etc. have low contrast it poses serious challenges for our readers living with dementia. It makes text difficult to distinguish from the background and creates visual clutter. This in turn just adds to other difficulties associated with dementia: slower processing speed, difficulty tracking lines, challenges decoding complex language structures.
So, poor contrast adds to the cognitive burden and it’s not surprising that reading can become frustrating.
But we all have – should have – the right to access information about our own lives so that we can make decisions independently for as long as possible. When we ignore elements like contrast, we’re actively disempowering our readers.
4. How can we improve the contrast of our documents?
So, how can we improve the contrast in the written information we produce?
Luminance
Firstly, let’s note that our brains rely heavily on differences in light and shadow (i.e., luminance) to perceive edges, shapes, and spatial relationships. This is what contributes to depth perception. When there’s strong contrast in brightness between objects and their background, it’s easier for us to tell what’s in front, what’s behind, and how far apart things are. So, if depth perception is affected – as we saw in the examples at the beginning – then greater contrast can help. (To read more about this, there’s an excellent summary on the WebAim website here.)
Guidelines
The main point of reference for contrast in documents is the Web Content Accessibility Guidelines (WCAG). Developed by the World Wide Web Consortium, the guidelines provide internationally recognised standards for making web content accessible to people living with a wide range of disabilities.
The guidelines grade contrast as either minimum contrast (AA) or enhanced contrast (AAA). Contrast is shown as a ratio. The minimum contrast we should aim for is 4.5:1 and enhanced contrast has a ratio of 7:1. These ratios can vary slightly depending on the size and nature of the text, but that’s the basic principle.
Generally, I believe it makes sense to use the enhanced contrast standard (AAA) whenever possible in dementia-friendly documents because:
Feedback from readers living with dementia overwhelmingly suggests that the better the contrast, the easier they find documents to read.
In general, there are so many other challenges facing readers living with dementia that it makes sense to keep things as easy as possible.
Some examples
What does good contrast look like in practice? Here are some examples. The examples in column 1 use colour schemes from actual online business documents aimed at customers living with dementia. The examples in columns 2 and 3 show possible tweaks to the colour schemes that would bring the contrast to enhanced, or AAA standard.
| Column 1 | Column 2 | Column 3 |
|---|---|---|
 |
 |
 |
| FAIL | AAA | AAA |
| Column 1 | Column 2 | Column 3 |
|---|---|---|
 |
 |
 |
| AA | AAA | AAA |
Conclusion: A Small Change, a Big Difference
When we provide accessible documents, people living with dementia are empowered to continue reading, understand information, and manage their own affairs. But don’t worry if you’re finding this complicated. There’s lots of online guidance and tools available to help. Still need help? Perhaps you’d prefer to hire me to work on a colour scheme with you, check contrast in existing documents, or just give you some training so that you can do it yourself.
And don’t forget that there’s a masterclass coming up next week to teach you exactly this. Register at: https:/subscribepage.io/ContrastMasterclass
Bibliography
Alzheimer’s Foundation of America (no date) Don’t Overlook Alzheimer’s Affect on Eyesight. Available at: https://alzfdn.org/dont-overlook-alzheimers-affect-on-eyesight/ (Accessed: 9 June 2025)
Alzheimer’s Society (no date) Factsheet 527: Changes in perception. Available at: https://www.alzheimers.org.uk/sites/default/files/pdf/sight_perception_and_hallucinations_in_dementia.pdf (Accessed: 9 June 2025)
Business Disability Forum (no date) Inclusive Communication Toolkit: Section 2 – Inclusive communication practical resources. Available at: https://businessdisabilityforum.org.uk/resource/inclusive-communication-toolkit/section-2-inclusive-communication-practical-resources/ (Accessed: 9 June 2025)
Dementias Platform UK (no date) Posterior cortical atrophy: a dementia that affects the vision. Available at: https://www.dementiasplatform.uk/news-and-media/blog/posterior-cortical-atrophy-a-dementia-that-affects-the-vision (Accessed: 9 June 2025)
Dementia Friendly Design | Social Care Wales (no date) Dementia-friendly design. Available at: https://socialcare.wales/resources-guidance/improving-care-and-support/people-with-dementia/dementia-friendly-design (Accessed: 9 June 2025)
EyeWiki (no date) Visual Variant of Alzheimer’s Disease. Available at: https://eyewiki.org/Visual_Variant_of_Alzheimer%E2%80%99s_Disease (Accessed: 9 June 2025)
The Good Care Group (no date) Sight and Perception in Dementia | Supporting a Person with …. Available at: https://www.thegoodcaregroup.com/news/sight-and-perception-in-dementia/ (Accessed: 9 June 2025)
Continual Engine (no date) The Importance of Color Contrast for Accessibility. Available at: https://www.continualengine.com/blog/color-contrast-for-accessibility/ (Accessed: 9 June 2025)
Villar, F., Serrat, R. & Bravo‑Segal, S. (2019) Giving them a voice: Challenges to narrative agency in people with dementia. Geriatrics, 4(1), p. 20. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6473304/ (Accessed: 9 June 2025).
