A ring that tracks sleep is worth wearing if the nights it describes feel like the nights you had, and if you forget it is on.
We compared finger sensors with a chest strap over a long stretch of ordinary sleep. The ring was convenient. It was not a lab.
What it can see
Optical sensors at the finger do well at whether you were asleep and roughly how long. Stages and heart-rate variability are estimates. A loose ring, a cold hand, or a night of tossing turns those estimates into fiction.
- A fit that does not spin and does not pinch.
- Charging you will actually do, because a dead ring records nothing.
- A willingness to treat stages as a sketch, not a diagnosis.
- Skin that can tolerate a ring worn overnight.
If the ring moves, the data moves with it, away from the truth.
Wearing it
Give it a consistent finger and a few dull weeks before you redraw your life around a score. Use the trend. Ignore the single dramatic night unless you also remember being awake.
Buy it as a convenient diary. Do not buy it as a doctor.
