Visual limitations range from low vision to blindness. Users with visual disabilities encounter problems when seeing text or images on a computer screen and when performing tasks that require hand-eye coordination, like moving a computer mouse. Text size and color can make a big difference in legibility for people with low vision.
Orca is a flexible, extensible, and powerful assistive technology for people with visual impairments. Using various combinations of speech synthesis, braille and magnification, the Orca Screen Reader and Orca Magnifier application enable users with limited or no vision to use the GNOME desktop and associated applications. The screen reader also supports Braille.
For a text-only guided setup, open a dialog with
Alt+F2,
enter Orca text-setup and press
Enter.
The first time Orca is launched you will be presented with a list of
languages from which to choose. Enter the ID number of your language
(for example, 7 for American English) and press
Enter.
When you run Orca for the first time, it will automatically enter setup
mode. If you want to run setup at some later point, you can pass the
setup option to Orca the next time you run it.
Furthermore, while Orca is running you can press Ins+Space to
bring up Orca's configuration GUI. Finally, Orca provides a text setup
utility that you can start by passing the --text-setup
option to Orca. All of these options will create a
~/.orca/user-settings.py file that holds your
Control Center and will also enable the accessibility infrastructure.
You need to log out and log back in for the new setting to take effect.
Start Orca by typing orca in a terminal session window. You can do so from a virtual console window if you do not yet have access to the GUI. With the GUI installed you can also press Alt+F2 to bring up the dialog and then type the command orca (followed by any optional parameters) and press Enter. Orca will automatically enter text setup mode if you run it from a virtual console window or if your GUI environment is not yet set up for accessibility.
To quit Orca press Ins+Q (or CapsLock+Q in laptop layout mode). A dialog will appear.
The braille page allows you to customize various aspects of braille usage.
The first control on the braille page is the check box. This check box toggles whether or not Orca will make use of a braille display.
Orca's braille monitor provides an on-screen representation of what takes place on the braille display. This feature is mostly for demonstration purposes, but is also useful for Orca developers who do not have access to a braille display.
The check box determines the manner in which role names are displayed and can be used to help conserve real estate on the braille display.
When checked, this feature tells Orca to not present the
$1 string at the end of a line.
The radio button group determines the amount of information that will be, in certain situations, converted to braille.
The magnifier page allows you to enable/disable magnification and specify how magnification is performed.
The first control on the magnifier page is the check box. This check box toggles whether or not Orca will provide magnification. This option, along with the ability to enable speech and to enable braille support, allows Orca to be tailored to meet the needs of a wide variety of users.
Two zoomer GUI controls determine magnification characteristics: , which sets magnification power and , which sets the location and size of the magnifier window.