Display brightness levels for the Venu® watches have multiple options to choose from. You can access the brightness menu on most Venu watches by following the steps below. For specific instructions, search Display Settings in your owner's manual.
Access the menu of your watch.
Select the Gear icon or Settings.
Select System.
Select Display.
Select Brightness.
To turn on auto-brightness select 
until you see the three sun options beside it. Once you have this selected you will have three options for the brightness level.
Low:
Medium:
High:
After selecting a brightness level it will automatically adjust based on the ambient light sensor to keep the device within the brightness setting you choose to make it easier to see in different lighting conditions.
If you would like to set the brightness level manually, select until you see only two sun options beside it. It should appear like the image below.
Once this is showing, you can select the bottom sun to lower the brightness, or the upper sun to raise it. It will adjust by 10% increments between 10% and 100% brightness.