Rendering this very page with Firefox, and magnifying its upper left corner with kmag

A screen magnifier is software that interfaces with a computer's graphical output to present enlarged screen content. By enlarging part (or all) of a screen, people with visual impairments can better see words and images. This type of assistive technology is useful for people with some functional vision; people with visual impairments and little or no functional vision usually use a screen reader.

Use

The simplest form of magnification presents an enlarged portion of the original screen content, the 'focus', so that it covers some or all of the full screen. This enlarged portion should include the content of interest to the user and the pointer or cursor, also suitably enlarged. As the user moves the pointer or cursor the screen magnifier should track with it and show the new enlarged portion. If this tracking is jerky or flickers it is likely to disturb the user. Also, the pointer or cursor may not be the content of interest: for example, if the user presses a keyboard shortcuts that opens a menu, the magnified portion should jump to that menu. Pop-up windows and changes in system status can also trigger this rapid shifting.

Screen magnifiers can be especially helpful for people with low vision, including elderly users. However, in a 2001 paper, Vicki Hanson noted that people with low vision often also have additional disabilities such as tremors.[1]

Features

Ranges of 1- to 16-times magnification are common. The greater the magnification the smaller the proportion of the original screen content that can be viewed, so users will tend to use the lowest magnification they can manage.[citation needed]

Screen magnifiers commonly provide several other features for people with particular sight difficulties:

Screen magnifiers bundled with an operating system

Stand-alone screen magnifier products

See also

References

  1. ^ V. L. Hanson (2001). "Web Access for Elderly Citizens". Proceedings of the 2001 EC/NSF workshop on Universal accessibility of ubiquitous computing providing for the elderly - WUAUC'01. Proceedings of the workshop on Universal accessibility of ubiquitous computing. p. 14. doi:10.1145/564526.564531. ISBN 158113424X. S2CID 290610. Retrieved 2017-02-14.
  2. ^ "Haiku User Guide - Magnify". Retrieved 2010-05-11.
  3. ^ GNOME Project: Magnification in GNOME Shell
  4. ^ "How-to: Mouse Magnifier". Microsoft Hardware. Microsoft. 2015. Archived from the original on 2016-06-08. Retrieved 2015-04-16. If the Magnify command was not assigned to a button on your mouse by default, you can assign it to one. [...] To turn on or turn off the Magnifier[:] Click the mouse button assigned to Magnify.
  5. ^ "OS X El Capitan: Zoom options in Accessibility preferences". Apple. 2016. Retrieved 2017-02-14.
  6. ^ "OS X Yosemite: Zoom pane of Accessibility preferences". Apple. 2015. Retrieved 2017-02-14.
  7. ^ "Use Accessibility features in iOS". Apple. 2016. Retrieved 2017-02-14.