OS X Mountain Lion Bible

Enabling Visual Assistance

The first section in the Accessibility system preference is Seeing, and its three panes' options improve the visual display of OS X or substitute visual information with audio equivalents. (The three panes are Display, Zoom, and VoiceOver.) The technologies available are designed to enable people with limited visual abilities to use the full OS X.

Setting display options

The first pane in the Seeing section is Display, which provides controls for the screen itself to make it more legible for some people's vision:

• Invert Colors: If selected, this option has OS X swap black with white and likewise swap Colors with their opposites (such as red with cyan, blue with orange, and green with purple)—displaying what is essentially a photographic negative.

• Use Grayscale: If selected, this option has OS X display the screen in all grays, rather than using colors.

• Enhance Contrast: This slider lets you set the contrast of the screen, forcing light shades to be white and dark shades to be black or their full colors. The slider ranges from Normal (the default) to Maximum, which essentially removes all shades other than white and the full color).

• Cursor Size: This slider lets you increase the size of the pointer (cursor) to be more easily seen on the screen. The slider ranges from Normal to Large.

• Open Display Preferences: This button opens the Displays system preference (see Chapter 27) to control other aspects, such as brightness and resolution.

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