Thanks for using Apple Support Communities.
For more information on this, take a look at:
iOS: Configuring accessibility features
Go to Settings > General > Accessibility. There are settings for the following features:
- Use three fingers and double-tap the screen to enable Zoom. If you need to increase the level of Zoom, use three fingers to double-tap and hold, then move your fingers up or down on the screen to increase or decrease magnification.
Best of luck,