Sleep science became a core pillar of the Ionic experience. The watch tracked sleep quality by analysing movement, heart rate, and the SpO2 sensor data to estimate changes in blood oxygen saturation monitored overnight. If the sensor detected levels below a user’s personal baseline, the app notified the wearer and offered tips for improving sleep hygiene. This integration of photoplethysmography with the red and infrared sensors enabled a richer picture of overnight physiology than previous wristbands. Collectors who demand granular control over their nightly biometrics can view the Omega selection for designs that emphasize detailed physiological metrics with classic mechanical elegance.