There are two types of text magnifications that people generally refer to:
screen enlargement software and closed circuit televisions (CCTVs). Computer
screen magnification for individuals who are visually impaired is essentially
analogous to an individual who is blind using speech synthesis; each of them
accessing the computer monitor. CCTVs for the visually impaired can be said
to be analogous to reading systems for the blind since both functions are attempting
to access printed material.
Screen enlargement software can magnify the text and graphics on a computer
screen in various ways. The Windows version software allows the user to magnify
a single line underneath the cursor, magnify an area of the screen, or magnify
the entire screen and the magnification can range from 1.5 times to 16 times
the normal size of characters. Depending upon the particular software, there
are also numerous other variations and combinations of the above features,
including an option to have the program automatically scroll through the document.
Screen enlargement software also allows the user to alter the color of the
text and the color background. For example, if the user is light sensitive
but needs contrast, they may wish to have the text displayed in bright yellow
on a soft gray or powder blue.
Screen enlargement can be used effectively with speech synthesis. If used in
tandem, the user can have certain features of an application program spoken
while their concentration is focused where they have the magnified text.
Closed circuit televisions (CCTVs) are essentially electronic magnifiers. There
are four basic types of CCTVs; these include: NTS interface, portable, stand
alone, and computer interface. The distinction between these units is mostly
in their configuration, but they all achieve similar purposes.