Lights emmiting from back

Discussion in 'Apple Watch' started by gelie, Jun 29, 2015.

  1. gelie macrumors regular

    Joined:
    Mar 7, 2010
    #1
    Im pretty sure when the salesperson helped me set up my watch i saw lights emitting from the back of the watch? If so why and how can i replicate this? thx
     
  2. menace3 macrumors 6502

    menace3

    Joined:
    Aug 13, 2008
    Location:
    Seattle, WA
    #2
    Depending on activity, it will light up. If you decide to check your heart rate right now, for example, the lights will light up and check for your heart rate.
     
  3. Armen macrumors 604

    Armen

    Joined:
    Apr 30, 2013
    Location:
    127.0.0.1
    #3
    swipe up on the watch face. This will take you to Glances. Swipe left/right until you find the heartrate glance. with that on screen the green lights underneath the watch light up.
     
  4. TimUSCA macrumors 6502a

    TimUSCA

    Joined:
    Mar 17, 2006
    Location:
    Aiken, SC
    #4
    It turns on occasionally throughout the day to check your resting heart rate. Otherwise, it turns on when you pull up your heart rate Glance or if you have an active workout.
     
  5. CellXor10 macrumors regular

    Joined:
    Apr 23, 2015
    Location:
    Connecticut, USA
    #5
    Yeah, what everyone else has said. Heart Rate monitors.
     
  6. CellXor10 macrumors regular

    Joined:
    Apr 23, 2015
    Location:
    Connecticut, USA
    #6
    Further info on "How Apple Watch Measures Your Heart Rate" from their website:

    "The heart rate sensor in Apple Watch uses what is known as photoplethysmography. This technology, while difficult to pronounce, is based on a very simple fact: Blood is red because it reflects red light and absorbs green light. Apple Watch uses green LED lights paired with light‑sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. When your heart beats, the blood flow in your wrist — and the green light absorption — is greater. Between beats, it’s less. By flashing its LED lights hundreds of times per second, Apple Watch can calculate the number of times the heart beats each minute — your heart rate. In addition, the heart rate sensor is designed to compensate for low signal levels by increasing both LED brightness and sampling rate."
     
  7. gelie thread starter macrumors regular

    Joined:
    Mar 7, 2010

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