The impact of disability is radically changed on the Web because the Web removes barriers to communication and interaction that many people face in the physical world. However, when websites, web technologies, or web tools are badly designed, they can create barriers that exclude people from using the Web. (, 2016)

Human – computer interactions, it is common to consider that there are at least three types of human subsystems involved.

A perceptual system, receiving sensory messages from the computer.

A motor system, controlling the actions that the user performs to provide input to the computer.

A cognitive system, connecting the other two systems, by integrating the sensory input received to determine appropriate user actions.

Graphic user interfaces in most modern computing systems, and in the majority of World Wide Web sites, the demands placed on the visual channel of the user’s perceptual system have been raised beyond the capabilities of a significant portion of potential Web users

It is essential that the Web be accessible in order to provide equal access and equal opportunity to people with diverse abilities. Indeed, the UN Convention on the Rights of Persons with Disabilities recognizes access to information and communications technologies, including the Web, as a basic human right. (, 2016)

Accessibility supports social inclusion for people with disabilities as well as others, such as elderly people, people in rural areas, and people in LEDCs.

There is also a strong business case for accessibility. Accessibility overlaps with other best practices such as mobile web design, device independence, multi-modal interaction, usability, design for older users, and search engine optimization. Studies show that accessible websites have better search results, reduced maintenance costs, and increased audience reach, among other benefits, gives an incentive for businesses to developing a Web Accessibility Business Case for organizations. (, 2016)

Hearing impairment: an individual satisfies the definition of hearing disabled when hearing loss is about 30 dB for a single frequency.

Visual impairments: a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses.

Physical impairments: a limitation on a person’s physical functioning, mobility, dexterity or stamina.

Cognitive and Learning Impairments: a classification that includes several areas of functioning in which a person has difficulty learning in a typical manner.






For example:

Transcripts for Podcasts

Just as images aren’t available to people who can’t see, audio files aren’t available to people who can’t hear. Providing a text transcript makes the audio information accessible to people who are deaf or hard of hearing, as well as to search engines and other technologies that can’t hear.

It’s easy and relatively inexpensive for website developers to provide transcripts for podcasts and audio files. There are also transcription services that create text transcripts in HTML format.



Some people cannot use a mouse, including many older users with limited fine motor control. An accessible website does not rely on the mouse; it provides all functionality via a keyboard. Then people with disabilities can use assistive technologies that mimic the keyboard, such as speech input.

Ref : (2016). Accessibility – W3C. [online] Available at: