There is only one physical button on the Envision Glasses: the power button.
The power button is located in the back of the glasses, near the charging port, on the inside surface. You can feel it slightly protruding out of the surface and it has a different texture. Do not confuse it with the circular Envision Logo, which also protrudes out, but is on the outside. The power button allows you to power the Envision Glasses on and off.
To power on your Envision Glasses, hold the button for 6 seconds. It takes about a minute to turn on the Envision Glasses. A power on sound will be played, after which the glasses are ready for use.
To turn off your Envision Glasses, press and hold the button for 3 seconds. You will hear a sound when the Envision Glasses initiate the power off process, which completes in 20 seconds.
You can also use the power button to put your device to sleep. Simply tap the power button once and your device will go to sleep.