Web Design for the Disabled
What disabilities will be discussed?
Cognitive and mental disabilities will not be discussed because of their immeasurable complexity. It should be mentioned that many techniques discussed here later on also support the users with cognitive and mental disabilities.
This research focuses mainly on visual, hearing, motor disabilities and combined disabilities.
Visual disabilities
About 45 million people worldwide are blind, while 135 million have impaired vision. The category of visual impairments contains full blindness, low vision, color blindness and selective impairments of parts of the visual field.
Color blindness is much more common with men than with women. Approximately one in 12 men has at least some color perception problems.
Actually everybody with limited eye sight, people carrying glasses or using contact lenses, falls into the group of visually impaired.
Hearing disabilities
Hearing disabilities like deafness and hard of hearing are often disregarded when designing for the web. It is true that it is not an issue in many cases. Nevertheless, possible issues should not be ignored. About 0.1% of the world population are deaf.
The amount of web sites based on multimedia or using multimedia for critical content increases daily. This includes audio and video files. Appropriate alternatives reduce the problem.
Motor disabilities
Motor disabilities complicate the handling of input devices, such as a standard PC mouse and keyboard. Many people can use a mouse for most tasks but have trouble with precise movements. Klicking a large button is easier for most users.
20% of the Australians with recorded disabilities indicate that physical disabilities affect their life most of all.
Combined Disabilities
Very often disabled people have more than one disability, either from a single cause or from multiple causes. This can make many everyday life situations much more difficult just like a broken arm together with a broken leg make it impossible to use crutches normally.
Web users who are deaf and blind cannot use the usual screenreader other blind people use or rely on captioning like deaf people without other disabilities. They are limited to technologies that can only be used by people with both disabilities, in this case maybe a refreshable braille keyboard. Assistive technologies will be discussed in the following chapter in more detail.
Deafness and low vision is a much more usual combination of disabilities. The effect is a bit easier because these users can use technologies like screen magnifiers.
The most common causes of multiple disabilities are age-related. Today more and more older people use the web. This number will definitely grow a lot in the next years especially because the older people in future will have more experience with the use of computer systems and the web from their younger years.
Low vision, hard of hearing and motor disabilities are very common age-related disabilities that will have to be considered since these people could find more opportunities to make their life easier due to what the web offers. Ordering groceries on web pages from online shops that deliver the goods to the doorstep can make life much more manageable for someone who does not have the strength to carry heavy bags. But what if this person has under average eyesight and has difficulties controlling the mouse well enough to hit the small shopping basket symbol because its size cannot be increased even when enlarging the font size?