The magnifier window allows you to zoom in on specific parts of your device's screen if they're otherwise difficult to read.
1.
From the Settings app, scroll to Accessibility.
2.
Tap Accessibility.
3.
Tap Visibility enhancements.
4.
Scroll to Magnifier.
5.
Tap Magnifier.
6.
Tap or slide the Magnifier shortcut to ON.
7.
Select your preferences on how to start or stop this function.
8.
Tap OK.
9.
You've completed the steps!
