How does sleep cycle app know when your asleep?
Apple Watch Sleep Tracking: How it actually works // Setup, Tested, Details, Comparisons
At times, when I go to bed and start falling asleep, I get a strange feeling, as if my head is very dizzy. There is a sound in the ears, similar to when you close your eyes tightly (muscle vibration), only stronger. At the same time, I can not open my eyes and generally move for a while. Is it ...