Maybe you have a MacBook with a small screen or a Mac mini connected to a TV or external monitor, and you feel like you could use a second screen or device to extend or mirror your current display.

It’s a familiar scenario — you’re looking at something on your iPhone and, all of a sudden, the screen turns to black and you have to interact with the handset to see what you were doing again. If ...

Alternately or in tandem, you may want to go to Settings > Accessibility > Display & Text Size and turn on Auto-Brightness.