How Do Computers for the Blind Work?

Visual impairment shouldn't keep anyone from using a computer.

For those with access, blind assistive technologies greatly expand personal and professional opportunities. After braille, no invention has been as revolutionary in allowing people who are blind or visually impaired to communicate, share, and receive information.

To make an environment as visually dependent as computers accessible to those unable to see, a blind assistive device must do two things:

  1. Allow users to read all onscreen content, whether emails, spreadsheet columns, articles, application toolbars, or photo captions.
  2. Provide a way to navigate the keyboard and desktop, open and use programs, and browse the web.

The two technologies that make this possible are screen access and screen magnification.

Screen Access Software

Screen readers give voice to computers. They synthesize written words and keyboard commands into human-sounding speech, sort of like the automated messages you hear on voicemail or customer service calls.

The most popular screen access program is JAWS for Windows. The program reads onscreen content and functions to the user, allowing people who are blind to launch programs, navigate their desktop, read documents, and surf the web using only their keyboard.

Here's an example: Rather than double-clicking on an icon to open the Chrome web browser, a person who is blind might use JAWS to do the following:

  • Select the Windows key to open the Start menu.
  • Listen to the list of options.
  • Select P to access the program list.
  • Select I to skip to the applications beginning with I.
  • Select the down arrow to scroll through the list.
  • Select Enter once they hear "Chrome."

It sounds painstaking, but screen readers can quicken the navigation process through shortcuts and audible cues. For example, the arrow keys allow users to quickly cycle through desktop items or section headings on a website. Selecting Insert + F7 displays a list of all the links on a page. On sites with search bars or input fields, JAWS emits a specific sound to indicate that the cursor is over a search box.

In addition to converting text to speech, another crucial function JAWS provides is output in braille. This function allows braille readers to read documents on refreshable braille displays, or to download them onto portable braille devices like BrailleNote.

The main drawback with screen readers is the price. The American Foundation for the Blind notes that prices can range up to $1,200. One can, however, download free Windows accessibility software, or purchase an all-in-one PC solution like CDesk.

Serotek offers a free program called System Access to Go, which is a web-activated screen reader that can be used on virtually any computer.

Screen Magnification Software

Screen magnification allows visually impaired users to enlarge or clarify content. In most programs, users can zoom in and out with a keyboard command or mouse wheel.

HumanWare's ZoomText Magnifier, one of the most popular such programs, can magnify screen content from 1 to 36 times while maintaining image integrity. Users can zoom in and out at any time with a turn of a mouse wheel. ZoomText provides controls so users can adjust:

  • Color, contrast, and brightness.
  • Letter thickness and spacing.
  • Size of the cursor and mouse pointer.

ZoomText users who'd like to use two applications at the same time can magnify portions of the screen by opening a separate "Zoom" window. An enlarged viewing area can also be expanded onto adjacent monitors.

The degree of vision loss usually determines which solution is best. People with no or severely limited vision might use screen readers. Those with moderately impaired vision might instead rely on screen magnification services.

Speech and Magnification Programs for Mac and iOS

It used to be that blind assistive technology was limited to PCs. Not anymore. Apple now has screen reading and magnification programs for both Mac OS X and iOS. The screen reader is called VoiceOver, while the magnification program is called Zoom.

VoiceOver 3 includes a standard set of hand gestures that can be used to navigate among different windows, menus, and applications. It can also integrate more than 40 popular braille displays via Bluetooth.

Zoom is activated using keyboard commands, onscreen buttons, and mouse or trackpad commands. It can magnify text, graphics, and motion video up to 40 times without loss of resolution.

Assistive Technology Training

No matter which technology one chooses, a person who is blind will probably need a computer, a screen reader, and some training to help learn how to use them. The sheer number of commands within JAWS is enough to constitute a language. Fortunately, there are a lot of training resources available:

  • Webinars from product makers and institutions like the Hadley School for the Blind.
  • Training materials in accessible formats from blind assistive tech companies like Handy Tech North America.
  • Post-assessment programs through a vocational rehabilitation agency or hospital.
  • Phone and audio tutorials from experts like Roger Cusson of Seeing Hands Enterprises.
  • Local continuing education courses and assistive technology user groups.

Training and product prices vary. Interested individuals can contact state agencies for funding assistance. Vocational rehabilitation services, commissions for the blind, and special education departments also often have their own financial assistance programs.

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