An Overview of Assistive Technology for People with Visual Impairments
Technology for people who are blind includes a number of devices that all enable the person to read and/or write information independently.
Braille Writing Equipment
The simplest and cheapest device for writing braille is the slate and stylus. The slate is a device consisting of a guide attached to a frame housing a number of evenly spaced braille cells. Paper is inserted between the guide and the frame. Using the stylus, the writer is able to punch out any combination of braille dots and thus produce hard copy braille.
The Perkins Braille is a machine very similar to a typewriter that allows for braille input and output. The Perkins brailler features a row of six keys, three on either side of a spacebar, as well as a line advancement key and a backspace key at either end of the keyboard.
COMPUTER ACCESS FOR PEOPLE WHO ARE BLIND
People who are blind or visually impaired access the computer using one of three modes of output: large print, synthetic speech, or braille. Most have learned to type well and are quite comfortable with using the computer keyboard. In fact, keyboard commands provide access to most of the same functions normally accessed using the mouse. Voice recognition software is not required by a person who is visually impaired.
Note: Very few options exist to provide access to operating systems other than windows 95 and later versions. Those that do exist are less well developed and not generally recommended for beginning users.
Large Print
Windows 98 and later versions provide an accessibility option which enables the user to enlarge the text on the screen. This is adequate for some people. Others, who may need larger print, use software which enables further enlargement of the text as well as the changing of foreground and background colors and, in some cases, synthetic speech output which supplements the large print. The two most popular programs are ZoomText, manufactured by AI Squared of Vermont, and Magic, manufactured by Freedom Scientific of Florida. Both companies offer demonstration versions as downloads from their Websites.
Synthetic Speech
People who cannot see well enough to read large print or who find reading for long periods of time to be tiring may use software which causes the text from the screen to be spoken via the sound card or another device, called a speech synthesizer. The quality of speech offered varies depending on the device, but it has improved greatly since its inception in 1939. The two most popular "screen readers," as these programs are known, are GW Micro's WindowEyes and Freedom Scientific's JAWS for Windows.
Users of synthetic speech output can take advantage of specialized keyboard combinations which cause the output device to read by line, paragraph, sentence, word, etc. One of the greatest disadvantages of using synthetic speech, however, is the difficulty it presents in enabling the user to form an accurate understanding of the layout of the screenwhen the screen reader does not read the information in its correct context. This problem may arise when incorrect methods have been used to format information or when the software has not been used previously with a screen reader and may employ new methods of displaying information which the screen reader does not "recognize". Furthermore, the latest versions of screen readers rearrange the text from pages which contain columns or tables significantly so that reading will be easier for people who are blind. This can prevent the blind user from knowing how the information was originally organized and how pieces of data relate to one another. Developers of screen readers are now including features that allow the user to get more information about text format and layout. Several companies and individuals also offer tutorials and training which can help blind people to gain a better understanding of how Windows presents information on the screen and how to use screen readers most effectively.
Braille Output
A third group of people use devices which provide a one-line praille display. Features of the device allow for exploring various areas of the screen. As the user moves around the screen using the controls, the line of braille, created by an array of pins, "disappears" and a new combination of pins from the array forms the braille translation of text from the new portion of the screen.
Braille displays are the most costly of the access options; however, they provide the best access for people working in customer service or programming environments. They also allow for a more realistic concept of the layout of the screen to be formed.
Braille displays work in combination with the same software which controls the production of synthetic speech. Users of braille displays will therefore incur additional costs when adapting a computer.
Problems for Users of Adaptive Computers
The graphical user interface, which is the basis for the Windows operating system, poses some problems for developers and users of adaptive software. Each graphic needs to be labeled, and alternatives to mouse commands need to be available. Many mainstream software companies have recognized this problem and are working with consumer groups and developers of screen access software to find acceptable solutions.
The use of JAVA programming on Webpages allows for the inclusion of controls which are completely dependent on the mouse (e.g. mouseover, hover, and drop-down menus which do not use submit buttons). These controls have been inaccessible for users who are blind until recently. The latest versions of JAWS and Window Eyes include features that allow blind people to access web pages with JAVA and other similar features.
Computers have opened many doors for people who are blind. Using the Internet, we can access current news independently as well as find useful information such as prescription information, recipes, technical and academic information, and much more. Blind people are not free from access problems; but they are closer to equality than they have ever been, and many blind people are contributing to the wealth of information online via their own Websites.
Notetakers and PDAs
A notetaker is a portable device which allows for word processing and selected other activities. A variety of notetakers are available and offer different features. Some allow the blind person to enter commands and information using a Perkins-style keyboard. Others feature a standard qwerty keyboard. Some provide only speech output while others feature a braille display. Many notetakers also include calculator functions.
The advantages of notetakers include portability, long battery life, quick start-up, and choice of keyboard style. Some parents and teachers favor early introduction of the notetaker as a braille writing tool because of the strength required to use the Perkins brailler successfully.
Manufacturers of notetakers have recently introduced new products that function like palmtop computers. These devices are larger than the palmtop but provide most of the same features as well as the features of a notetaker. Currently, two of these devices are available: the BrailleNote from PulseData and the PAC Mate from Freedom Scientific. Each of these has advantages and disadvantages.
The BrailleNote is an older product and is therefore more widely known. Rather than providing access to mainstream programs for palmtop computers, the BrailleNote features programs designed intentionally to work with the KeySoft speech and braille output software. These programs include a word processor, Web browser, email program, calendar, address management program, and calculator. ActiveSync allows access to the file system from a PC. The BrailleNote includes an optional screen for visual display.
The PACMate is a unique product which includes a detachable braille display that can also be used with a standard computer. Like the BrailleNote, the PAC Mate includes a specialized word processor and calculator. However, since it uses the same operating system that other PDAs use, it allows the user to run mainstream programs like Pocket Word, Pocket Outlook, and Pocket Internet Explorer. This makes the PAC Mate as compatible with the PC using ActiveSync as any other PDA is. If a person is already using JAWS on a computer, he will be able to transfer most of this knowledge to use of the PAC Mate since speech and braille output is provided by JAWS for Pocket PC. The PAC Mate can also be connected to a computer for remote viewing.
The Mountbatten Brailler
The Mountbatten Brailler combines the features of a notetaker, a braille translator, the Perkins brailler, and a braille embosser into one unit. It is larger than a notetaker, and paper can be inserted as in the Perkins brailler. Input from the Perkins-style keyboard can be sent directly to the paper or saved into memory.
The Mountbatten can translate Grade II braille to text and send the text to a computer or printer. It can also accept text from a computer and create a hard copy of the text, functioning as an embosser. These features make the Mountbatten a useful tool for people who are working with young children and need to produce materials in braille. However, the Mountbatten may not be suitable for high-volume braille production.
Braille Translation Software
Braille translation software converts computerized print into braille. Programs are now available which convert mathematics text into Nemeth or music into braille music notation. For more information about translation software, visit:
Closed-Circuit Televisions
Closed-circuit televisions (CCTVs) display magnified text from a page on a screen. Many CCTVs also allow the user to select different background and foreground colors. This is a useful feature for people who find that reading light text on a dark background is easier. Some CCTVs are portable.
People who have a fair amount of vision may be comfortable using a CCTV for long reading assignments for which a magnifier is not suitable. People with less vision may use the CCTV for reading mail or short pieces of information while relying on other modes of reading for longer work. The American Foundation for the Blind (AFB) publishes a document, "Video Magnifiers," which provides more detailed information about CCTVs and where to buy them.
Braille Embossers
An embosser accepts the contents of a text file or a file created by translation software and creates a braille hard copy, just as a printer creates a print hard copy. Braille embossers may "print" on one or both sides of a page and may produce braille at up to 56 characters per second.
Scanners and OCR Software
Scanners send an image of a page to a computer, where optical character recognition (OCR) software interprets the text from the image and feeds it to the screen reader. A scanner and OCR software can enable a blind person to read most books and many magazines independently.
Some OCR programs are very compatible with screen readers. Specialized OCR programs are also available that provide additional features which are useful for people with visual impairments. Examples include Freedom Scientific's OpenBook and Xerox's Kurzweil.