If you head to settings > display > screen timeout. You can adjust the length of time which the device display stays active without any interactions.
If you're device support you can also enable keep screen on while viewing, while you're screen timeout settings page.
Hopefully this will help you and make it so you don't have to keep a finger on the screen.
Just a side the keep screen on while viewing works 95% of the time.
My settings are 15 seconds & KSNWV enabled.
MrBindex | Tech enthusiast