Change Accessibility Zoom preferences on Mac
On your Mac, use the Zoom pane of Accessibility System Preferences to make the entire screen larger or to enlarge just the area where the pointer is located.
To change these preferences, choose Apple menu 
> System Preferences, click Accessibility, then click Zoom.
Use keyboard shortcuts to zoom | Use the listed shortcuts to zoom in and out. For example, to zoom in, press Option-Command-Equal Sign. When this option is selected, you can use the shortcuts on the login screen to make the password field appear larger. |
Use scroll gesture with modifier keys to zoom | Hold down the selected modifier key while scrolling with your trackpad or the scroll wheel on your mouse. For example, with the default trackpad settings, press and hold the Control key and drag two fingers up (to zoom in) or down (to zoom out). |
Smooth images | Make zoomed images appear smooth. |
Zoom follows the keyboard focus | Magnify the area that has the keyboard focus. |
Enable Touch Bar zoom | If your Mac has a Touch Bar, display a larger version of it on the screen. See Zoom in on the Touch Bar. |
Speak items under the pointer | Have your Mac identify items under the pointer only when you use zoom or all the time. You can set whether to have your Mac wait a shorter or longer time before speaking. |
Zoom Style | Zoom the entire screen (Full screen) or just the area where the pointer is located (Picture-in-picture). |
Options | Specify options for full-screen or picture-in-picture zoom. |
To quickly enable or disable Zoom using the Accessibility Options shortcut panel, press Option-Command-F5 (or if your Mac has Touch ID, quickly press Touch ID three times).
You can enable keyboard shortcuts for some zoom options in the Accessibility section of the Shortcuts pane of Keyboard preferences. To open the pane, choose Apple menu > System Preferences, click Keyboard, then click Shortcuts.