Take advantage of the accessibility features in OS X when you use iTunes to sync information and content from your iTunes library to iPhone. In the Finder, choose Help > Help Center, then search for “accessibility.”
TTY supportYou can use the iPhone TTY Adapter cable (sold separately in many areas) to connect iPhone to a TTY machine. Go to www.apple.com/store (may not be available in all areas) or check with your local Apple retailer.Connect iPhone to a TTY machine: Go to Settings > Phone and turn TTY on, and then connect iPhone to your TTY machine using the iPhone TTY Adapter.When TTY on iPhone is turned on, the TTY icon appears in the status bar at the top of the screen. For information about using a particular TTY machine, see the documentation that came with the machine.Minimum font size for mail messagesTo increase readability, you can set the minimum font size for Mail message text to Large, Extra Large, or Giant.Set the minimum mail message font size: Go to Settings > Mail, Contacts, Calendars > Minimum Font Size.The Large Text setting overrides this minimum font size.Assignable ringtonesYou can assign distinctive ringtones to people in your contacts list for audible caller ID. You can purchase ringtones from the iTunes Store on iPhone. Visual voicemailThe play and pause controls in visual voicemail let you control the playback of messages. Drag the playhead on the scrubber bar to repeat a portion of the message that’s hard to understand. Widescreen keyboardsMany apps, including Mail, Safari, Messages, Notes, and Contacts, let you rotate iPhone when you’re typing, so you can use a larger keyboard.Large phone keypadMake phone calls simply by tapping entries in your contacts and favorites lists. When you need to dial a number, iPhone’s large numeric keypad makes it easy. Voice ControlVoice Control lets you make phone calls and control Music playback using voice commands.Closed captioningTurn on closed captioning for videos: Go to Settings > Videos > Closed Captioning.Not all video content includes closed captions.