15% of the global population – over a billion people – lives with some form of disability
World Health Organization
Disability is a mismatch between a person and their environment. Assistive technology helps fix that mismatch.
Lightbulbs are assistive technology for the vision dependent.
Tom Dekker
Assistive technology usually means:
Screen readers
A screen reader is a form of assistive technology(AT) [1] that renders text and image content as speech or braille output. Screen readers are essential to people who are blind,[2] and are useful to people who are visually impaired,[2] illiterate, or have a learning disability.[3] Screen readers are software applications that attempt to convey what people with normal eyesight see on a display to their users via non-visual means, like text-to-speech,[4] sound icons,[5] or a Braille device.[2] They do this by applying a wide variety of techniques that include, for example, interacting with dedicated accessibility APIs, using various operating system features (like inter-process communication and querying user interface properties), and employing hooking techniques.[6]
wikipedia – screen reader
Screen magnification software
A screen magnifier is software that interfaces with a computer’s graphical output to present enlarged screen content. By enlarging part (or all) of a screen, people with visual impairments can better see words and images. This type of assistive technology is useful for people with some functional vision; people with visual impairments and little or no functional vision usually use a screen reader.
wikipedia -screen magnifier
Alternative input devices
For users with physical disabilities a large variety of switches are available and customizable to the user’s needs varying in size, shape, or amount of pressure required for Some people may not be able to use a conventional input device, such as the mouse or the keyboard, therefore, it is important for software functions to be accessible using both devices. Ideally, software will use a generic input API that permits the use even of highly specialized devices unheard of at the time of software’s initial development.
wikpedia – computer accessibility