on my reading portion as i did right there, it switches in seven mill second. that s faster than you can blink an eye. three times faster than you can blink your eye. same thing in turning it off. when i swipe to put it in the automatic mode it reacts just as quickly. when i say automatic mode there and an accelerator in the temple that senses head tilts. if i constantly look down at my computer screen, i don t want to go on and off. i simply swipe the temple, put it in the automatic mode, i look down, automatically the reading portion comes on, i look up, it turns off. it is absolutely fascinating. of course. it is all in the accelerometer. it seems to be running on battery power. how long can a charge last you? a charge will get you three to four days. what you do with empower frames, put them in your charger the same way you would your ipod or ipad or cell phone.