Change the display settings on your device by following these steps:
1. Go to 
Settings > Device > Display
2. Choose from the following settings. Some of these settings may vary by your device and version of Android. All can affect battery life.
Brightness Level
Move the 
Slider to set the brightness level on your device
Adaptive Brightness
Turn on Adaptive Brightness to automatically optimise the brightness level on your device based on the available light around you. Adaptive Brightness is enabled by default. You can still adjust your brightness when needed.
Sleep
Change how long it takes for your device’s screen to go black when you’re not using it
Daydream
Set up screen savers that display photos, colourful backgrounds, and more when your device is charging or docked.