Web Access Centre

Screen magnification software

Summary: Screen magnification software is used by people with partial eyesight, sometimes alongside a screen reader.

• How it works
• Accessibility essentials
• Web accessibility links

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Technologies used to browse the web:

• Speech and braille output
• Screen magnification
• Text-based browsers
• Graphical browsers
• Return to how people with disabilities access the web

As with screen readers and refreshable braille displays, screen magnification software works together with the operating system and web browser to enlarge the contents. Generally this is very large, and far exceeds the largest settings that a standard operating system has in its settings. It is the software of choice amongst people with low vision.

How it works

Screen magnification does just what it says, and simply magnifies the screen. The degree of magnification can vary according to the preferences of the person using it. The greater the level of magnification required results in less information that can be displayed on screen. In some instances the magnification can be so extreme that only two or three words are displayed on the screen at a time.

Most people who use screen magnification also change the contrast and colour settings to make it easier to read. For example, they may set a black background with white text to make it stand out more.

Accessibility essentials

There are a number of issues to be considered for people who use screen magnification. A major drawback, but one that is easy to rectify, is where there are large areas of blank space between text and elements. This need to scroll through large areas of blank space can make it very difficult for someone to find elements in a page with ease. They may not even realise that there is anything to find at the other end of a large blank space, and simply assume it is the end of the content.

For example, imagine a form where the text labels such as “Name” have too much space between it and the text input box. Good judgement is essential in laying out page and the elements it contains.

Images also do not scale well, and become blurred and pixelated when magnified. This can cause problems of legibility if these are images of text. For example, navigation could become incomprehensible and unusable if images of text is used as links.

The following example shows how an image of text begins to break up when magnified just a few times. This distortion effect will increase dramatically with the extreme magnification that is commonly used by someone with low vision:

Clear and consistent layout is also very important for people who depend on screen magnification. Having navigation links in the same place on each page helps people gain familiarity with the site, and helps them learn where information can be found quickly. Inconsistent layout and navigation can be extremely frustrating, and so should be avoided.

Web accessibility links

• Types of disability
• Accessibility myths
• How people with disabilities access the web

For Web Access Centre updates email webaccess@rnib.org.uk

Content author: webaccess@rnib.org.uk

Last updated: 20/10/2008 15:51