Types of disabilities that affect web use (and the $1.9 trillion business case)

When businesses think about their website audience, they often picture a “typical” user: someone who can see the screen clearly, use a mouse, hear audio, and process information quickly. But this picture omits a large number of people, and a lack of disability awareness in how we build digital products is largely why.

According to the World Health Organization (WHO), an estimated 1.3 billion people worldwide live with a significant disability. That’s 16% of the global population, or roughly 1 in every 6 people, and this number is only growing as populations age and chronic health conditions become more common.

If your website doesn’t work for people with disabilities, you’re not only creating a frustrating experience, but you’re also locking out a market with real economic power: an estimated $1.9 trillion in annual disposable income, according to the Return on Disability Group.

In this post, we break down the main types of disabilities that affect how people use the web, so you can understand who your users are and what steps to take toward building a site that works for all of them.

Visual disabilities

Visual disabilities range from partial sight loss to complete blindness, and include conditions like color blindness that many people don’t immediately associate with disability.

The numbers

The WHO estimates that at least 2.2 billion people globally have some form of vision impairment. Of those, approximately 43 million are blind, and 295 million have moderate-to-severe vision loss.

How it affects web use

People with visual disabilities rely on assistive technologies such as screen readers, which convert on-screen text into speech or Braille. They may also use screen magnifiers to enlarge content, or adjust their browser settings to increase text size and change color contrast.

What goes wrong on inaccessible sites

Images without text descriptions (alt text) are invisible to screen readers. Low contrast between text and background makes content hard to read for people with partial sight. Color-coded information (like “red means error”) is meaningless to someone with color blindness. When a website doesn’t work properly with screen magnification, content may overlap, disappear, or become impossible to navigate.

Who this includes (and some you might not expect)

  • People with age-related macular degeneration
  • People with cataracts or glaucoma
  • People with color blindness (approximately 300 million people worldwide, mostly men)
  • People with diabetic retinopathy
  • Anyone recovering from eye surgery or dealing with a temporary eye injury

Auditory disabilities

Auditory disabilities include everything from mild hearing loss to complete deafness. For many people with disabilities in this category, sign language (not written language) is their first language, which means written web content can itself be a barrier.

The numbers

Over 1.5 billion people worldwide live with some degree of hearing loss, according to the WHO. Of those, 430 million have hearing loss severe enough to require treatment. By 2050, that number is expected to rise to over 700 million.

How it affects web use

Audio and video content without captions or transcripts is inaccessible to people who are deaf or hard of hearing. Podcasts, webinar recordings, product demo videos, and even auto-playing background audio all create barriers when there’s no text alternative.

What goes wrong on inaccessible sites

Videos play without captions. Audio-only content (like podcast embeds) has no transcript. Alerts and notifications rely on sound alone with no visual indicator. And for users whose first language is sign language, dense, jargon-heavy written content can be harder to process than for a native reader of that written language.

Who this includes

  • People who are deaf from birth
  • People with age-related hearing loss (one of the most common conditions in older adults)
  • People with noise-induced hearing loss from occupational or environmental exposure
  • People with conditions like tinnitus or Menière’s disease
  • Anyone with a temporary ear infection or ruptured eardrum

Motor disabilities

Motor disabilities affect a person’s ability to use their hands, arms, or other body parts to interact with a computer. As one of the types of disabilities most directly tied to how people physically use a website, this covers a broad spectrum, from mild difficulty with fine movements to full paralysis.

The numbers

The WHO reports that 1.7 billion people globally live with musculoskeletal conditions, making these the leading contributor to disability worldwide. More specific motor conditions include Parkinson’s disease (over 10 million people globally) and cerebral palsy (2 to 3 in every 1,000 children).

How it affects web use

People with motor disabilities may not be able to use a mouse at all. They navigate websites using only a keyboard, voice commands, eye-tracking devices, switch controls, or other adaptive tools. Some can use a mouse but have difficulty with precise movements, such as clicking small buttons or navigating dropdown menus.

What goes wrong on inaccessible sites

Small clickable areas (tiny buttons, closely spaced links) are difficult or impossible to hit. Dropdown menus that require a mouse hover don’t work for keyboard users. Time limits on forms force users to start over if they type slowly. And if a website can’t be navigated with a keyboard alone, it’s completely unusable for many people with disabilities of this kind.

Who this includes

  • People with arthritis (one of the most common causes of motor difficulty)
  • People with Parkinson’s disease, multiple sclerosis, or cerebral palsy
  • People with repetitive strain injuries (RSI)
  • People with spinal cord injuries or limb amputations
  • Anyone with a broken arm, hand injury, or post-surgical limitations

Cognitive disabilities

Cognitive disabilities are the most diverse and often the least understood of the types of disabilities we’re covering here. They affect how people process information, focus attention, remember things, and make decisions.

The numbers

Estimates suggest that 15 to 20% of the global population is neurodivergent in some way. Dyslexia alone affects roughly 10% of the world’s population and accounts for about 80% of all learning disabilities. ADHD affects an estimated 6 to 10% of children and 3 to 4% of adults.

How it affects web use

People with cognitive disabilities may need more time to read and understand content. They may struggle with complex navigation, inconsistent layouts, or pages overloaded with information. Flashing or moving content can be distracting or disorienting. And unclear language like jargon, double negatives, or ambiguous instructions can make an otherwise simple task feel impossible.

What goes wrong on inaccessible sites

Walls of unbroken text with no headings or visual structure. Navigation menus that change location or labeling between pages. Auto-playing animations or videos that can’t be paused. Unclear error messages that don’t explain what went wrong or how to fix it. And forms with confusing field labels or instructions that assume prior knowledge.

Who this includes

  • People with dyslexia, dyscalculia, or other learning disabilities
  • People with ADHD
  • People on the autism spectrum
  • People with intellectual disabilities
  • People with traumatic brain injuries
  • People experiencing cognitive decline from aging, medication side effects, or conditions like early-stage dementia

The four categories at a glance

Disability typeGlobal population (approx.)Common web barriersWhat helps
Visual2.2 billion with vision impairment, 43 million blindMissing alt text, low contrast, color-only cues, broken zoomAlt text, contrast ratios, text resizing, screen-reader-friendly markup
Auditory1.5 billion with hearing lossUncaptioned video, no transcripts, audio-only alertsCaptions, transcripts, visual notifications
Motor1.7 billion with musculoskeletal conditionsMouse-only navigation, small click targets, strict time limitsKeyboard navigation, larger targets, generous timeouts
Cognitive15 to 20% of the population is neurodivergentDense walls of text, inconsistent layouts, unclear errorsPlain language, clear structure, predictable navigation

The disabilities you don’t see: temporary and situational

Here’s where disability awareness gets especially relevant for businesses. Disability isn’t always permanent or visible, and the types of disabilities that affect your users on any given day are far broader than most teams account for.

Temporary disabilities are short-term conditions that limit a person’s abilities for days, weeks, or months. A broken wrist that prevents mouse use. An eye infection that makes screens painful. A concussion that makes reading difficult. An ear infection that blocks hearing.

Situational disabilities are limitations created by a person’s environment rather than by a medical condition. Trying to watch a video in a noisy airport without headphones (you need captions). Using your phone in bright sunlight (you need high contrast). Holding a baby in one arm while browsing on your phone (you need one-handed navigation). Working in a second language (you need clear, simple text).

These situations are universal, and almost everyone will experience some form of temporary or situational disability in their lifetime. The curb-cut effect applies here: features designed for people with disabilities, like captions, keyboard navigation, clear language, and high contrast, end up helping everyone.

When you build your site with accessibility in mind, you’re not just serving the 1.3 billion people with permanent disabilities. You’re building a better experience for every visitor, in every situation.

The business case: $1.9 trillion in spending power

Disability awareness matters as a moral and human issue, but there’s also a clear business case that’s hard to ignore.

People with disabilities represent an estimated 1.85 billion consumers globally, with $1.9 trillion in annual disposable income, according to the Return on Disability Group. When you include their families and close networks (people who are directly influenced by their purchasing decisions), that figure rises to over $13 trillion.

And yet, research consistently shows that most of the web remains inaccessible. The AccessibilityChecker.org study of 10,000 websites found that over 70% were not aligned with current accessibility guidelines.

That’s a massive gap between the size of the audience and businesses’ readiness to serve them.

On the legal side, regulations like the European Accessibility Act (EAA) are raising the bar for digital accessibility across industries. Businesses that don’t act now face growing legal risk as enforcement increases worldwide.

But beyond compliance and revenue, there’s something simpler at play. When someone can’t use your website, they leave. They don’t contact support. They don’t send feedback. They just go to a competitor whose site works for them, and you lose the sale without ever knowing it happened.

What you can do about it

Understanding the types of disabilities that affect web use is the first step. Here’s how to move forward:

Learn the basics. If you’re new to web accessibility, start with Accessibility 101. It covers the core concepts without overwhelming you with technical details.

Think about design from the start. Inclusive design means considering the full range of human diversity when building your site, not adding accessibility as an afterthought.

Check where you stand. An accessibility tool like iubenda’s Accessibility Widget can help you spot common issues across your site and give your visitors more ways to interact with your content.

Keep the bigger picture in mind. Accessibility isn’t a one-time project. As your site grows and changes, so do your users’ needs. Build it into your process, not just your checklist.

Frequently asked questions

How many people worldwide live with a disability?

The World Health Organization estimates that 1.3 billion people (about 16% of the global population) live with a significant disability. That number is rising as populations age and chronic conditions become more common.

What is the spending power of the disability community?

People with disabilities represent roughly 1.85 billion consumers globally and an estimated $1.9 trillion in annual disposable income, according to the Return on Disability Group. When families and close networks are included, the figure rises to over $13 trillion.

What are the main types of disabilities that affect web use?

The four main types of disabilities are visual (vision loss, color blindness), auditory (hearing loss, deafness), motor (limited or no use of hands and arms), and cognitive (dyslexia, ADHD, autism, learning differences, and others). Each creates different barriers and calls for different design choices.

What are temporary and situational disabilities?

Temporary disabilities are short-term limitations like a broken wrist, an eye infection, or a concussion. Situational disabilities come from your environment, like watching videos in a noisy place without headphones or holding a baby in one arm. Almost everyone experiences both at some point, which is why accessible design benefits all users.

Why should businesses invest in disability awareness now?

Three reasons: the audience is large and underserved (over 70% of websites aren’t aligned with accessibility guidelines), the spending power is significant ($1.9 trillion), and the legal pressure is growing through regulations like the European Accessibility Act (EAA). Businesses that wait risk losing customers and facing enforcement at the same time.

What’s the easiest way to start improving accessibility?

Run an accessibility check on your site to find the most common issues (missing alt text, low contrast, keyboard-only navigation gaps), then fix those first. Tools like iubenda’s Accessibility Widget can address many widespread issues quickly while you plan deeper structural improvements.

Everyone benefits from an accessible web

The 1.3 billion people with disabilities worldwide aren’t a niche audience. They’re your customers, your employees, your partners, and your neighbors. Add in the millions more who experience temporary and situational disabilities every day, and the picture is clear. Disability awareness isn’t a specialist concern. It’s relevant to everyone who builds for the web.

When you build a website that works across all four types of disabilities (visual, auditory, motor, and cognitive) you’re building a site that works better for all your visitors and opening your business to a market with enormous spending power that most of your competitors are still ignoring.

The question isn’t whether you can afford to invest in accessibility. It’s whether you can afford not to.

Ready to take the first step? Explore iubenda’s Accessibility Widget and see how it can help you build a more inclusive site today.

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