For Seniors: How to Turn on Zoom on Your iPhone 4S
The iPhone 4S Zoom feature lets you enlarge the screen even more than the standard unpinch gesture does. The Zoom feature enlarges the contents displayed on the iPhone screen when you double-tap the screen with three fingers.
Tap the Settings icon on the Home screen and then tap General. In General settings, drag your finger up to scroll down the screen and tap Accessibility.
The Accessibility pane appears.
In the Zoom pane, tap the Zoom On/Off button to turn on the feature.
Tap the Home button to close Settings. At this point screens will be enlarged (zoomed). You need to swipe with three fingers to scroll down the Home screen and locate the icons in the Dock along the bottom.
Tap Safari and go to any website and double-tap the screen using three fingers; it enlarges.
Press three fingers on the screen and drag to move it around.
Double-tap with three fingers again to go back to regular magnification.
Tap the Home button to close Settings.
The Zoom feature works almost everywhere in iPhone: in Photos, on web pages, on your Home screens, in your Mail, in Music, and in Videos — give it a try!