How people with impairments use the internet

Website accessibility is about providing equal access to all users, regardless of ability, technology or situation. Website accessibility, contrary to popular belief, does not just affect people with visual impairments. It also addresses the needs of a much wider audience, including people with dyslexia, those with restricted upper body mobility, the hard of hearing and the elderly.

One of the most important factors in understanding website accessibility is to understand how a user with an impairment actually uses the internet.

It is equally important to remember that people are different. Impairments vary from person to person, over time and even between different people with the same type of impairment. People can have combinations of different impairments and varying degrees of severity.

Users who have some form of impairment that hinders their use of a computer may use special hardware or computer programs to aid them. These are called assistive technologies and enable impaired people to accomplish tasks that able people accomplish without difficulty. There are many kinds of assistive technologies available and the type of assistive technologies somebody may employ depends on their impairment and ability.

Visual impairments and blindness

Internet users who have very low vision or are totally blind may rely on a screen reader such as Jaws for Windows to navigate the internet.

A screen reader is a piece of software that interprets the content of a web page. This interpreted content is converted to digitised speech and ‘read’ to a user through their speakers.

The interpreted content from the screen reader may also be sent to a refreshable Braille display for the user to interpret. Refreshable Braille involves the use of a mechanical display where pins can be raised and lowered dynamically to allow any Braille characters to be created.

Partial and poor vision

There are many types of partial sight problems a user may have:

Poor acuity - vision that is blurred
Tunnel vision - seeing only the middle of the visual field
Central field loss - seeing only the edges of the visual field
Clouded vision

To explore the internet people with low vision may use extra-large monitors, increase the size of the text on the screen, while others may use screen magnifiers.

Some users may prefer specific combinations of text and background colours that make using the computer easier; such as a large bright yellow font on a black background. Others may choose fonts and colours that they find easier to read.

Visually impaired people can also use text only browsers such as Lynx to browse the internet. Text only browsers display the text of a web page but do not support images and many other visual components of websites.

Colour blindness

Colour blindness is defined as ‘a lack of sensitivity to certain colours’. It is usually inherited and present from birth or can occur due to damage to the eye or brain.

There are several forms of colour blindness. By far the most common form is red/green colour blindness which involves the confusion of red and green, and can have the following effects:

Different shades of red appear dull and indistinct
Inability to distinguish between greens, oranges, pale reds, and browns. These colours appear the same, only being distinguishable by their brightness

Rare forms of colour blindness can cause blue and yellow to be indistinguishable. In very rare cases all colours are seen in black and white.

It is estimated that as many as one in 20 men and one in 200 women have some form of colour blindness. (Source: Institution of Electrical Engineers)

As with people with low vision a colour blind user may have a specific combination of text and background colours that they find particularly suits their needs. They may choose to override background and text colours of a website with colour combinations of their own.

Hard of hearing and deafness

Hard of hearing and deaf internet users are able to access information on a website in much the same way as somebody who does not have an impairment. The obvious difference is that they may have difficulty in understanding audio content.

Some deaf users’ first language may be sign language and may not be able to read a written language clearly.

Restricted mobility

This is a very broad category and can include weakness, limitations of muscular control (such as involuntary movements, lack of coordination or paralysis), limitations of sensation, joint problems or missing limbs.

It is important to remember that restricted mobility problems can be either long term or short term. For example; a user who has broken their arm and temporarily cannot use a mouse.

Some physical impairments can include pain that impedes movement such as arthritis or an injury. These conditions can affect the hands and arms as well as other parts of the body.

To use the internet people with restricted mobility affecting the hands or arms may use a very wide variety of assistive technologies. Examples of these are:

Specialised mouse and keyboard that may be much larger for ease of use
A single handed keyboard
A pointing device such as a head-mouse, head-pointer or mouth-stick
Voice-recognition software; so users can ‘tell’ the computer what to do

Epilepsy

Epilepsy is termed as a ‘hidden disability’ as it is not obvious like some other impairments. Epileptic users access websites in much the same way as someone who is not impaired in any way.

Epileptic internet users may have images, animations and other multimedia turned off in their web browser as seizures can be triggered by visual flickering between 2 and 59 flashes per second or by certain frequencies of audio. (Source: Rich Media Accessibility)

Others

There are many other groups of people who will benefit from having an accessible website. These groups can include people whose first language is not English, children, the elderly or people who are from outside your industry and may not understand technical phrases or jargon used.

Conclusion

The numbers of internet users who may have difficulties accessing a website are somewhat astounding:

10 million - The number of people with some form of registered disability in the United Kingdom. (Source: Employers’ Forum on Disability)
2 million - The number of UK residents with sight problems. (Source: RNIB)

Although there is likely to be some overlap between these groups it is estimated that approximately 48% of the UK population could potentially have difficulty in using a website.

The combined spending power of these people is estimated to be £80 billion. (Source: Department for Work and Pensions). This is a market that is currently being ignored by the majority of businesses in the UK due to a lack of understanding and outdated web design practices.

Further Information

For further information on how users with impairments access the internet please read:

How People with Disabilities use the Web: http://www.w3.org/WAI/EO/Drafts/PWD-Use-Web/Overview.html
Royal National Institute for Deaf People (RNID) fact sheets and leaflets: http://www.rnid.org.uk/information_resources/factsheets/
Mencap - Am I making myself clear: How to write for people with learning difficulties; http://www.mencap.org.uk/download/making_myself_clear.pdf (1mb)

Article originally published February 2006. Contributed by David Randall, an Accessibility Consultant for Intelligent Environments Europe Ltd.