For all the Ryze Smart Watches, you can turn on the screen with two methods.

1. Click a button or tap the screen to turn on the screen, preferrable if you wish to interact with it.
2. Raise your arm and turn your wrist towards you, this should turn the screen on without interacting physically if you wish to check the time or see an update on any current activities.

Some of the models also allow you to turn off the screen by covering it with your hand, but usually leaving your wrist in a neutral position with no action that is bringing attention towards the watch will cause it to turn off on its own anyway.