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Computer magnification

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Screen magnification software enlarges the image presented on the computer screen without eliminating or altering the data in any way. These programs run in the background and do not interfere with the normal use of the computer except when the user wants to adjust the accessibility feature (ex. increase the magnification).



Why wouldn't a person just use a larger font size?

Without screen magnification software, a person with low vision may choose to increase the size of text (font) in his or her document to make the words easier to read. However, when he or she finishes editing the document, the font size must be reduced before printing in order to maintain a 'professional' appearance. Some software will also allow the user to zoom in or out of a page to magnify the text up to 5x. Screen magnification software will increase the image of the document, for any software, without changing the font size. In addition, screen magnification programs will enlarge not only text, but also icons and graphics on the screen.

Is there a Windows setting to change the icon text?

In Windows, it is possible to enlarge the text on icon labels by adjusting the Accessibility Options (one of the Settings / Control Panel choices) to High Contrast. This increases the font size slightly, and gives the user the option of displaying white text on a dark background. This might be a good option for someone who only needs a slight adjustment.

Would using a larger monitor help?

Using a larger monitor will cause the information on the screen to look larger, but will provide less than 2x magnification. This might be a good option for someone who needs the information to be only slightly larger. When used along with magnification programs, larger monitors can also allow a person a larger part of the screen. However, the additional cost of the largest monitors may be more than the cost of other assistive technology options, and may not be as effective.

How well do physical magnifiers that are mounted on a monitor work?

Fairly well, and they may also provide some anti-glare features to improve readability. However, these products are designed to provide only lower levels of magnification. Additionally, some products cause screen distortion at the edges (and can be tiring to use).

Are there disadvantages with using this technology?

The difficulty with screen magnification is that, once magnified, the entire image does not fit on the computer monitor. The user must use a mouse, or other pointing device, to scroll across the image. The movement required to view the entire image increases with higher magnification.

People considering computer magnification should also determine whether they are able to read at a reasonable speed with the magnification. If too much effort is needed to just identify each letter, it may be more practical to use other technology, such as voice output software.

What features can help a person keep track of where he or she is on the screen?

  • At lower magnifications, use a feature to enlarge just the information at the cursor. This provides an enlarged box at the area of the screen where the person is working, but he or she can still see the layout of the other parts of the screen.
  • At higher magnifications, 'tracking bars' may help. These are reversed color areas on the top and side of the display to show what part of the screen is being magnified. They move as the cursor moves.

What other software features should be considered?

  • The ability to present the magnified image in different formats. For example: full screen magnification; split screen or box magnification (the magnified image is confined to one portion of the screen); magnifying glass (the enlarged image moves with the mouse, as with a magnifying glass).
  • The ability to have multiple magnification windows.
  • The ability to identify a specific area to be magnified.
  • Status tracking features that will draw the user's attention to information being displayed outside of the current field of vision, such as letting the user know when another window pops up.

Can the screen contrast be changed?

Increase in contrast can improve readability. Light colors on dark backgrounds provide the highest contrast. Windows 95 and later versions offer Accessibility Options in the control panel that include high contrast colors and screen enlargement. The enlargement feature is not intended to be a replacement for dedicated magnification software.

Can only the cursor be enlarged?

There is some software (RJ Cooper's Biggy, Applied Human Factor's Mouse & Caret Buddy) that makes the cursor larger, higher contrast or place additional visual cues near the cursor.

Can both magnification and voice output be used?

Some magnification programs include some basic voice output capabilities. Note that those programs are designed for people with low vision, and they do not have all of the features that would be included in voice output software for an individual who is blind. Other magnification programs are compatible with the more popular voice output software and/or voice output software made by the same manufacturer.

Can a CCTV / Video Magnifier be used to provide computer magnification?

A few CCTVs are computer compatible and will allow a user to display the information from the computer on the CCTV, with magnification and contrast options, instead of on a computer monitor. These products easily switch between reviewing printed and computer information, or may allow both to be displayed on a split screen. For computer access, however, the types of magnification options are usually more limited than those provided by computer software. Check with CCTV vendors to determine whether their product line includes a computer-compatible video magnifier.

How hard is it to learn to use this technology?

Some training is required, but once the system is set up to fit the needs of the user, the settings rarely require adjustment.

What type of computer is needed?

It is available for most Windows and Macintosh operating systems, with a larger number of products available for the Windows environments.

How much does it cost?

Magnification software typically costs $400 to $700.


The Screen Magnifiers Homepage Product reviews, downloadable demos, news releases regarding product updates, discussion forum. By Peter Verhoeven.


Author: Karen Milchus
Affiliation: CATEA, Georgia Tech.
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