From the home screen, scroll down to the extended app list, and select Settings > Display & Brightness.

Brightness

Sets the brightness level of the screen.

Auto Backlight

Automatically adjusts the backlight brightness based on the ambient light.

Surface Screen Timeout

Sets the length of time before the screen turns off when not in dive mode.

NOTE: The dive computer turns off entirely when there are no button presses for 30 minutes outside of a dive.

Touch

Enables the touchscreen.