Use Hover Text on Mac
With Hover Text on your Mac, you can move the pointer over text on the screen to display a larger version of it, and display a larger version of text as you type.
Turn on Hover Text
On your Mac, choose Apple menu
in the sidebar, then click Zoom on the right. (You may need to scroll down.)Turn on Hover Text.
Show a larger version of text when you move the pointer over it
After you turn on Hover Text, move the pointer over text on the screen, then press the Command key to display a larger version.
Tip: Have the Hover Text window automatically displayed when you move the pointer over text, without needing to press a key every time. Choose Apple menu in the sidebar, then click Zoom on the right (you may need to scroll down). Click the Info button 
next to Hover Text, then turn on “Triple-press modifier to set activation lock.” To turn activation lock on or off, quickly press the Command key three times.
You can change the key you press to activate Hover Text and activation lock. Click the “Activation modifier” pop-up menu, then choose another key.
Show a larger version of text as you type
After you turn on Hover Text, you can display a larger version of what you’re typing as you type.
On your Mac, choose Apple menu
Click the Info button
next to Hover Text, click the “Text-entry location” pop-up menu, then choose a location.
As you type, a larger version of what you’re typing is displayed in a window at the location you specified.
Customize the appearance of Hover Text
On your Mac, choose Apple menu
Click the Info button
next to Hover Text, then change any of the following:The text size and font of the text shown in the Hover Text window
The colors used for the text shown in the window and the window itself