How Visually Impaired
People ‘see’ your online information
Last month we discussed website accessibility and the
adaptations you can easily make to your site, to meet both your
customers’ requirements and your legal obligations.
In this issue we look in more detail at the various types of
specialist computer software available, that help visually impaired
people ‘see’ their computer screen. We also give you 10 top tips on
how to design your website for users with this software.
There are three common aids a visually impaired person may use
to access a website depending on their level of vision:
- Screen readers or synthesizers - these are
usually used by people with very little or no useful
vision;
- Screen magnifiers - often used by people with some functional
vision; and
- Enlarging the text in your web browser - for those with less
severe forms of visual impairment.
1) Screen readers or synthesizers
People with least vision will usually use a screen reader to
access on-screen computer information. This reads out all on-screen
text, including what a person is typing. Examples of this software
are Jaws, HAL and LookOUT.
Screen readers will usually have different synthesised voice
options, as well as speed and volume control. They will recognise
Windows dialogs, icons, buttons, menus and controls; announce font
and style information; and read icons and Internet graphics labels.
Some Screen readers can be used in conjunction with a screen
magnifier if preferred.
2) Screen Magnifiers
If you have only moderate sight loss you could try using a
screen magnifier. Some users will magnify the screen so that only
three to four words are able to appear on the screen at any one
time. Magnification is usually up to 16 times, and sometimes 32
times. There are various options available including:
- A Screen Ruler: This magnifies any strip of
the screen that you point to with your mouse. The rest of the
screen remains at the original size, although you can have the
background dimmed out if desired to make the highlighted text even
more clear.
- Full feature magnifier: makes the whole screen bigger, usually
magnifies up to 16 times and sometimes 32 times. Magnifiers can
often also change the appearance of the cursors and mouse pointer
and alter the colours of text, foreground and background. Examples
include Zoomtext and Magnus.
- A magnifier that is used in conjunction with a screen reader
e.g. DUAL and Supernova
3) Browser enlargement
This is not specialist software - most browsers can enlarge the
text of a web page e.g. Internet Explorer and Netscape. This
feature can be useful for many people with sight difficulties. Some
sight is required and the text can not be enlarged as much as if a
screen magnifier is used.
Through changing your browser settings you can, for example,
change the default font for web pages, change the default colours
for web pages and change the colours of hyperlink text.
Tips to make your website screen reader and magnifier
friendly:
- Writing your website - use standard HTML
format, as this is the only format screen readers are likely to be
able to access.
- Layout - always put your most important information at the top
of your web page e.g. instructions at the top of web forms rather
than below them. Screen readers will read a page from top to
bottom. Screen magnifier users can only see a small section of the
screen at any one time, so if instructions are placed in an
out-of-the-way place they are likely to be missed.
- Headings - always include on-page headings. Although a website
may appear to have a heading for sighted people, you need to also
label it as a heading within the HTML code, so that the screen
reader recognises it is a heading. Also, make sure the page heading
accurately reflects the contents of the page, so the user does not
listen to a whole page unnecessarily. Also, remember to use a large
font size for headings so that people using magnifiers, or their
browser settings, will find them easily.
- Do not "freeze" the font sizing on your site - this will
prevent a person enlarging text with their browser. Use a CSS
script if possible.
- Links - avoid general links such as ‘click here’. A screen
reader can give the user a list of links on a page, to help them
navigate around web pages more quickly. Therefore, non-descriptive
links such as this are useless. Users of screen magnifiers will
have to search the surrounding text to find out where the link
goes.
- Images - do not embed text within images as a screen reader
will not be able to access the text, and images can become very
blurry, and therefore illegible, using a screen magnifier. If
images are needed then always use ALT text. The screen reader will
read this out to the user. Otherwise your images will be
‘missed.’
- Colours - Use good colour contrast. Also - separate different
sections of the page with background colours and borders. This
helps users of screen magnifiers, who can often only see one tiny
section of a web page at any one time, navigate the page and better
understand the page layout.
- Moving or flashing text - avoid this. People using a magnifier
may not have time to find, or read, the text before it disappears,
and screen readers will often miss it.
- Use list tags within your HTML code for lits, where possible.
Screen readers tell the user how many items are in a list before
reading it, so they know what to expect.
- Online documents - Screen readers are usually unable to access
PDF documents effectively, so provide standard text documents
instead or in addition.
We hope these tips give you a useful starting point. Visit our
online shop www.a2i.co.uk to see
the computer access products that we sell.
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