Web Accessibility is defined as the practice of making Web pages accessible to people using a wide range of user agent software and devices, not just standard Web browsers. This is especially important for people with disabilities such as visual impairment. In order to access the Web, some users require special software or devices in addition to a standard web browser, or specially designed web browsers.
The needs that Web accessibility aims to address include:
- Visual: Visual impairments including blindness, various common types of low vision and poor eyesight, various types of color blindness;
- Motor/Mobility: e.g. difficulty or inability to use the hands, including tremors, muscle slowness, loss of fine muscle control, etc., due to conditions such as Parkinson's Disease, muscular dystrophy, cerebral palsy, stroke;
- Cognitive/Intellectual: Developmental disabilities, learning disabilities (dyslexia, dyscalculia, etc.), and cognitive disabilities of various origins, affecting memory, attention, developmental "maturity," problem-solving and logic skills, etc.;
- Auditory: Deafness or hearing impairments, including individuals who are hard of hearing;
- Seizures: Photo epileptic seizures caused by visual strobe or flashing effects.