How Do Smartphones Know When You're Tired?

Smartphones can tell when you're tired because they watch how long your eyes stay open and how much you move. When your phone sees you blink a lot or stop moving, it thinks you might be sleepy. It uses the camera on your phone to look at your face and even checks if you're using your phone less during the day.

Take the quiz →

Examples

  1. Your phone notices you're blinking a lot during your lunch break and suggests you take a short nap.
  2. When you're sitting in class and not moving for a long time, your phone thinks you might be sleepy.
  3. You stay on your phone past 10 p. m., so it assumes you’re not going to sleep soon.

Ask a question

See also

Discussion

Recent activity