The needs of screen magnifier users are overlooked when
implementing web accessibility on to a website. Screen magnifiers
are used by partially sighted web users
to increase the size of on-screen elements. Some users will magnify
the screen so that only three to four words are able to appear on
the screen at any one time. You can try using a screen magnifier
yourself by downloading the
Zoomtext screen magnifier for a free 30 day trial.
The good news is that some of the basic principles for improving
accessibility and usability for screen magnifiers users, also
increase usability for everyone. To help, Webcredible have listed six
ways to improve accessibility and usability for screen magnifier
users:
1. Don't embed text within images
Text embedded within images can become blurry
and pixelated when viewed in screen magnifiers, and
therefore completely illegible. This is especially true when the
image text is rather poor quality, so if you absolutely have to
embed text within images then make sure the image is of high
quality. Many screen magnifier users can find it quite difficult to
read text at the best of times, so when it appears fuzzy to them it
can become difficult to impossible to read.
It's not usually necessary to embed text
within images anymore, as most presentational effects can
now be achieved with CSS. By embedding text within images the
download time of each page can become significantly greater due to
the weight of these images - for users on dial-up modems it can be
a real pain waiting for these images to download and render.
If you're not sure if a piece of text on the page is embedded
within an image or not, try highlighting the text. If you can
highlight each letter individually then the text is real text and
isn't embedded within an image.
2. Clearly separate sections of the page
Different sections of each web page should be clearly separated
through the use of borders and different background colours. Screen
magnifiers users can only see one tiny section of a web page at any
one time so it can sometimes be hard for these
users to orientate themselves within the page.
By using a blue background colour for the navigation, for
example, screen magnifier users can quickly move through the page
and when they see a blue background they instantly know that the
content are has finished and the navigation area begun.
Likewise, by separating different sections of the page with
borders, when a screen magnifier user moves over that border they
know they're moving into a different section. One especially common
form of this, is using a vertical bar to separate horizontal
navigation items.
Separating different sections of the page with background
colours and borders doesn't only increase usability for screen
magnifier users - it increases usability for
everyone. When regularly sighted users scan through a web
page, if the content, footer and navigation are all effectively
differentiated it's very easy to quickly gain an understanding of
the on-page layout.
3. Use clear and descriptive headings often
When screen magnifier users move their magnifier across the
screen one of the items that stand out to them is headings. By
ensuring heading text is large, and perhaps by differentiating it
through the use of colour, it will stand out to these users.
Screen magnifier users usually have to stop the movement of the
magnifier when they want to read a piece of text, so when they see a heading, they can stop and read it.
Because headings (in theory at least!) describe the content
contained beneath them, screen magnifier users can read a heading,
gain an understanding of the content beneath it, and decide whether
they want to read that content or not. If not, they can simply move
the magnifier down the screen and stop at the next heading.
Headings are incredibly useful for fully sighted users too for
essentially the same reason. When you scan through a web page,
headings are one of the items that stand out to
you. Again, you can read the heading (or listen to it for a
screen reader user), and provided its descriptive, instantly gain
an understanding of the content beneath it. You can then keep
reading or skip on to the next heading down the page.
4. Ensure link text is descriptive of its
destination
Link text such as 'click here' and 'more' should be avoided and
replaced with link text that adequately describes the link
destination. Link text, along with headings, is one of the items that stands out to screen magnifier
users (and all users for that matter) when browsing a web page. If
'click here' is used then these users (and in fact all users) will
have to search through the text before and after the link in order
to work out its destination.
5. Avoid scrolling or flashing text
Scrolling or flashing text is generally known for offering poor
usability, as it means that users can't read the text in their own
time. This is doubly true for screen magnifier users who read web
pages at a slower rate - chances are that they
won't have time to read the text at all before it
disappears.
6. Front-load paragraph content
By front-loading paragraph content, screen magnifier users can
access the main point of each paragraph
immediately. Front-loading means placing the conclusion
first, followed by the what, why, when, where and how. By placing
the conclusion first, screen magnifier users can read the
conclusion of the paragraph straightaway and then decide whether
they are interested in reading the rest of the paragraph or
not.
If screen magnifier users aren't interested in the content of a
paragraph, they can move the magnifier down the screen and when
they see white space they know that the paragraph has ended and the
next paragraph begun.
This rule about front-loading paragraph content actually
benefits absolutely everyone. By putting
the conclusion at the start of the paragraph, all users can
instantly gain an understanding of the point of the paragraph and
decide whether they want to keep reading it (or skip to the next
paragraph).
Conclusion
All-in-all, there are quite a few things that can be done to
improve usability and accessibility for screen magnifier users. The
good news though is that all of them improve usability for
absolutely everyone.
© WebCredible 2005
See: http://www.webcredible.co.uk/
Editor's note: OUT-LAW.COM will become much
more accessible and usable this month.
