Increase the size of what’s on the Mac screen
Your Mac comes with built-in controls to make it easier to see text and other content on the screen — increase the text size, zoom in on the screen and more.
Make text bigger
Adjust the size of text across multiple apps, as well as text and icons on the desktop and in sidebars. Choose Apple menu 
in the sidebar. Click Display, then click “Text size” and move the slider left or right.
Enlarge text you’re reading or typing
Move the pointer over text or icons to display a larger version, or see what you’re typing in a large text window. Choose Apple menu in the sidebar. Click Hover Text, then turn on Hover Text, Hover Colour or Hover Typing.
Zoom in on the screen
Magnify the entire screen or use an adjustable onscreen lens to zoom in to a part of it. Choose Apple menu in the sidebar. Click Zoom, then turn on a setting — like “Use keyboard shortcuts to zoom”.
Make everything on the screen larger
Your Mac automatically uses the best resolution for your display, but you can reduce the resolution to make everything on the screen appear larger. Choose Apple menu 
in the sidebar, then click Larger Text.
Tip: You can also quickly zoom in and out on images, web pages and PDFs with gestures like pinching or tapping on your mouse or trackpad. See the Apple Support article Use Multi-Touch gestures on your Mac.