Digital accessibility is the practice of building websites, apps and documents so that people with disabilities can actually use them: perceive the content, operate the controls, and understand what is going on. It is not a separate product for a separate audience. It is the same product, built so it does not quietly exclude a quarter of its users.
That fraction is not rhetorical. Roughly 1 in 4 adults lives with a disability affecting vision, hearing, movement or cognition. Many rely on assistive technology: a screen reader that speaks the page aloud, captions on video, a keyboard instead of a mouse, or screen magnification. If the product only works with a mouse and sharp eyesight, these users are locked out no matter how good the design looks.
Disability is also not a fixed group you are either in or out of. Ability moves along a spectrum, and everyone slides along it during a normal week.
| Ability | Permanent | Temporary | Situational |
|---|---|---|---|
| Seeing | Blindness, low vision | Recovering from eye surgery | A screen in bright sunlight |
| Hearing | Deafness | An ear infection | A noisy train, a silent office |
| Using hands | One arm, tremor | A broken arm in a cast | Holding a baby, carrying bags |
Every row shares a fix. Captions serve the deaf viewer, the commuter on the train, and the parent with a sleeping child alike. Design for the permanent case and the temporary and situational cases come along for free.
Accessibility is not an edge case worth 1 percent of the budget. Between permanent, temporary and situational limits, it describes every user on some day of their life.