So, we’ve already tackled the Theoretical Models of Disability (read the Theoretical Model post here), and now it’s time to understand the Categories of Disabilities. Because if we claim to care about accessibility but don’t understand disabilities, the real-life barriers people face, the tech that empowers them, and the strategies they use to navigate an inaccessible world we are not doing it right.
Accessibility isn’t just about slapping an alt text on an image or fixes… it’s about people. Real humans who navigate a world that often ignores, excludes, or straight-up works against them. If we don’t get this part right, we’re missing the entire damn point.
In this post we’ll talk about different disability categories, the obstacles people deal with, assistive technology that actually helps, and the adaptive strategies they use to function in an inaccessible world. Oh, and I’m throwing in some hard-hitting stats—because numbers don’t lie, and they might just change the way you see things.
The CPACC Book of Knowledge (BOK) defines disabilities into nine categories:
🔹 Visual
🔹 Auditory
🔹 Deafblindness
🔹 Mobility, Flexibility, & Body Structure
🔹 Cognitive
🔹 Speech & Language
🔹 Seizures
🔹 Psychological/Psychiatric
🔹 Multiple/Compound
Before we start let’s review this glossary check:
Assistive technologies are products, devices, systems, or items used by people with disabilities to perform tasks they could not do otherwise. Assistive technologies are also called adaptive technologies or adaptive software when used with computers.
Not all assistive technologies are computer-based, for example, communication boards made of cardboard are a type of assistive technology.
Adaptive strategies are tweaks and adjustments that people with disabilities use to perform daily living activities. These strategies increase their independence and ability to participate in society. Examples of adaptive strategies include using custom color combinations, moving closer to a speaker, and using alternative formats for printed materials.
Now let’s move on and break it all down.
Visual Disabilities: Seeing the Barriers 👁️
This category includes conditions affecting sight, such as blindness, low vision, and colour blindness.
The Reality: Imagine waking up and your phone screen is a blur. Now imagine trying to navigate a website where everything is poorly contrasted, buttons have no labels, and text is tiny as hell. That’s a daily struggle for millions.
Stats that should wake you up:
- 2.2 billion people globally have vision impairment or blindness.
- 1 billion of those cases could’ve been prevented or treated. (Healthcare gaps, anyone?)
- The leading causes of vision impairment globally are uncorrected refractive errors and cataracts.
- Most people with vision impairment are over 50 years old.
- 90% of people with vision impairments live in low-income settings.
- Color blindness? Red-green deficiencies affect 1 in 12 men and 1 in 200 women.
- About 246 million people, or 3.5% of the world’s population, have low vision.
Common barriers: Challenges with digital interfaces, reading printed materials, and navigating physical environments, flat interfaces and controls, low contrast, unreadable fonts, lack of screen reader compatibility, and no alt text.
Accessibility: Providing text alternatives for images, using high contrast colour combinations, ensuring website content is compatible with screen readers, and providing braille labels in the physical environment.
Assistive Technologies: Screen readers, screen magnifiers, refreshable braille displays, canes, and service animals.
Adaptive Strategies: Use of custom colour combinations and colour filters.
Auditory Disabilities: A World on Mute 🎧
Encompasses various degrees of hearing loss, deafness, and Central Auditory Processing Disorder (APD).
The Reality: Ever watched a video on mute and struggled to follow along? Now imagine everything was like that—with no captions, no transcripts, and people just expecting you to “hear” information.
Stats that hit hard:
- 430 million people have disabling hearing loss.
- 750,000 people in the EU use sign language as their first language.
- 5% of the global population has Central Auditory Processing Disorder (CAPD)—meaning they can hear but struggle to process sounds.
Common barriers: No captions, bad auto-generated captions, lack of transcripts, video calls with no interpreter, and audio alerts with no visual backup(Doorbells or other alarms)
Accessibility: Providing synchronized captions and transcripts for audio and video, using visual alerts and haptic feedback for alarms, and providing sign language interpretation for live events.
Assistive Technologies: Hearing aids, cochlear implants, assistive listening systems, and text-to-speech software.
Adaptive Strategies: Lip reading and using sign language.
Deafblindness: Double the Barriers, Half the Consideration 🏴☠️
The Reality: People think being deafblind means living in complete darkness and silence—it doesn’t. Most deafblind individuals have some residual sight or hearing, but communication is a daily battle.
Stats that make you rethink things:
- 0.2% to 2% of the world’s population is deafblind.
Common barriers: Lack of tactile interfaces, inaccessible emergency alerts, zero consideration in digital spaces.
Assistive Tech & Adaptive Strategies: Refreshable braille displays, haptic feedback devices, and ProTactile sign language.
Speech & Language Disabilities: When Words Don’t Come Easy 🗣️
It includes conditions like stuttering, apraxia, aphasia, dysarthria, speech sound disorders, and muteness.
The Reality: Ever had laryngitis? Now imagine trying to navigate a voice-activated world without speech.
Stats that need attention:
- 5-25% of children have speech sound disorders.
- 1-2% of adults struggle with speech difficulties.
- 2 million people in the U.S. have aphasia.
Common barriers: No text-based alternatives, lack of AAC (Augmentative and Alternative Communication) support, and reliance on voice-only interactions.
Accessibility: Providing text-based alternatives for voice communication, such as chat and forms.
Assistive Technologies: AAC devices, text-to-speech programs, alternative keyboards, and speech-generating software.
Adaptive Strategies: Use of gestures, facial expressions, blinking and communication boards.
Mobility Disabilities: A World Not Built for Wheels ♿
This category involves challenges with manual dexterity, fine motor control, ambulation, muscle fatigue, and body size.
The Reality: If stairs were optional, wheelchair users wouldn’t be stuck outside half the time. But hey, keep building places without ramps.
The stats that should embarrass architects:
- 11% of U.S. adults have mobility disabilities.
- 1% of the world’s population has rheumatoid arthritis.
- 12.5% of adults have obesity, which can impact mobility.
Common barriers: No ramps, tiny doorways, inaccessible public transport, open doors, and handling objects with fine motor skills. Websites with no keyboard navigation or tiny precise clicks.
Accessibility: Providing ramps and elevators in addition to stairs, wide doorways and hallways, automatic doors, and ensuring keyboard accessibility for digital content.
Assistive Technologies: Alternative keyboards, mouth sticks, speech recognition software, wheelchairs, and mobility scooters.
Adaptive Strategies: Use of devices such as reachers and grab bars to assist with daily tasks.
Cognitive Disabilities: When the System Is the Problem 🧠
This category encompasses conditions that affect cognitive functions such as thinking, memory, learning, and perception.
It includes intellectual disabilities, reading disabilities/dyslexia, math disabilities, ADHD, Autism Spectrum Disorders (ASD), and Non-Verbal Learning Disability (NLD).
The Reality: The world expects everyone to learn, process, and focus in the same way. Spoiler: They don’t.
This category is vast and super important, especially when creating digital products,
- ADHD: Difficulty with focus, attention, and impulse control
- Intellectual Disabilities: Limitations in reasoning, learning, and problem-solving
- Dyslexia: A reading disability that affects a person’s ability to read
- Dyscalculia: The inability to understand arithmetic and how to calculate
- Dysgraphia: The inability to draw or copy figures and graphs
- Autism Spectrum Disorders (ASD): Difficulties with social communication and interaction, and repetitive behaviours
- Non-verbal learning Disability (NLD): Difficulties with social skills, sensory input, and transitions
The stats that make you rethink education:
- 200 million people worldwide have an intellectual disability.
- ADHD among children is estimated between 2 and 7% globally, and around 4% in adults.
- It is estimated that 5 to 10% of the population has dyslexia.
- Estimated 3 to 6% of people have dyscalculia.
- 1 in 100 people have autism.
- 1 in 100, or 1%, of children in the United States may have NLD.
Common barriers: Information overload, hard-to-read content, and no flexibility in learning/workspaces. Difficulties with complex designs, problem-solving, processing information, and short-term memory.
Accessibility: Creating simple, predictable, and organized designs, simplifying user interfaces, using plain language, and providing information through text, audio, and images.
Assistive Technologies: Computer-based prompting applications, time management apps, audio notetakers, and screen readers.
Adaptive Strategies: Use of memory aids, distraction-free environments, flexible work accommodations, visual alternatives to text, and task management apps.
Seizure Disorders: Flashing Lights Are Not a Joke ⚡
This category includes conditions characterized by seizures, such as epilepsy and photosensitive epilepsy.
The Reality: Epilepsy isn’t just “falling down and shaking.” Seizures vary, and flashing content online can be straight-up dangerous.
The stat you need to remember:
- 50 million people have epilepsy globally, which means that it is one of the most common neurological diseases.
Common barriers: Flashing animations, lack of seizure warnings, and inaccessible emergency systems.
Accessibility: Avoiding flashing or strobe-like effects in digital content, and providing media controls to stop animations.
Assistive Technologies: Flicker-free monitors, seizure response wearables, monitor glare guards, and non-glare glasses.
Adaptive Strategies: Using media controls to stop animations.
Psychological Disabilities: When the Barrier Is Stigma 🧩
It includes anxiety disorders, mood disorders, schizophrenia, personality disorders, and eating disorders.
The Reality: Mental health isn’t an “excuse.” Anxiety, PTSD, and schizophrenia all impact how people interact with the world.
Stats that show the scale:
- The prevalence of anxiety disorders across the world varies from 2.5 to 7% by country.
- In 2017, an estimated 284 million people experienced an anxiety disorder, making it the most prevalent mental health disorder.
- Schizophrenia affects approximately 24 million people or 1 in 300 people worldwide.
Common barriers: Stigma, lack of workplace support, and environments that trigger symptoms. Challenges in managing emotions or stress and difficulty with mental functions and cognition.
Accessibility: Providing structure and clear instructions in both physical and ICT environments, as well as simplified communication methods.
Assistive Technologies: Apps for mood, stress, and anxiety management, as well as text-to-speech software and reminder devices.
Adaptive Strategies: Mindfulness and cognitive behavioural therapies to reduce stress and anxiety.
Multiple Disabilities: Because Life Isn’t One-Size-Fits-All 🔀
Many individuals experience multiple disabilities at the same time, which means their barriers are layered, complex, and often completely overlooked.
What Does This Mean in the Real World?
A Deaf individual with ADHD might struggle with captions that move too fast or a sign language interpreter who doesn’t pace communication in a way that works for them.
Someone with a mobility disability and a visual impairment might need both screen readers and voice-controlled smart home devices to navigate daily life.
A person with psychological disabilities and chronic pain might need accommodations that support both mental well-being and physical comfort, like flexible work schedules and ergonomic setups.
These overlapping conditions mean that accessibility isn’t just about fixing one issue, it’s about understanding how different barriers interact.
The Numbers Don’t Lie
Studies from the UK and Australia indicate that 10–15% of people with disabilities have complex needs—meaning they experience more than one significant impairment.
Many aging adults develop multiple disabilities over time, such as vision loss, mobility issues, and cognitive decline, making multi-faceted accessibility solutions essential.
Assistive Tech & Adaptive Strategies
People with multiple disabilities often layer different solutions to create accessibility that actually works for them:
1. Speech-to-text + predictive text tools: (for people with speech disabilities and motor impairments)
2. Screen readers + voice control: (for users who are both visually impaired and have limited mobility
3. Captions + simplified layouts: (for those who are Deaf and have cognitive processing challenges)
Final Thoughts:
I know it seems overwhelming, but If you’re prepping for CPACC, you need to learn this inside and out because real people depend on professionals who actually get it. And if this post made you rethink some things? Good. That’s the point. 😎
Stay tuned for the next post in the CPACC Prep Series; you can also listen to this episode podcast that I generated with my notes on Spotify. Listen to the podcast here