Use the Camera as a Magnifier
The iPhone 8 and iPhone 8 Plus camera can replace a pocket magnifier, allowing you to easily read small print on a menu or document without taking a picture and then zooming in.
Go to Settings -> General -> Accessibility -> Magnifier -> On.
Triple click the home button to turn the Magnifier on.
Now you can use a slider at the bottom of the screen and it will zoom in. Unlike simply using the camera to zoom in, this is easier to control and it makes it much easier to read text that is small.