On-Head Detection will automatically activate your device whenever you put it on and make Glass inactive whenever you take it off. That way, you don't have to remember to press the power button every time you put it on and off, and it might save you some battery life in the process.
Enable On-Head detection from the Settings bundle. Once enabled, put Glass on and and you’ll hear a chime while the display activates.
Take Glass off and you’ll hear a falling chime, indicating that Glass is now inactive. It's still powered on, but the touchpad and display won’t operate, no chimes will sound, and Glass won’t pick up incoming phone calls. For those fleeting photo opportunities, the camera button will still work while inactive.
If you have screen lock on, Glass will lock when you take it off. If they're off for more than 10 seconds, you'll be required to unlock the device whenever you put them on again.
Enable On-Head Detection from the Settings card. You'll be prompted to take Glass off for a moment and then put it back on again. This calibrates the device to your head and makes the feature more reliable. If you ever find On-Head detection isn't working as well as you'd like, say if Glass picks up calls while off your head or doesn't activate immediately when you put it on, try recalibrating the feature from the Settings card.