Light level detection

1. What it does

Measures the level of ambient light in your bedroom using the ambient light sensor (lux sensor)

When awake detection is enabled, light is being measured during sleep tracking.

You will see light level plotted on your sleep graph (in the same way as heart rates or breath is plotted), in LUX units.
#dark / #light tags will be added to your sleep records.
If there is disturbing light (see the table below for details) after sunset, we consider it as an Awake period.

Note Sensitivity of light-based awake detection can be further adjusted in Settings → Sleep tracking → Awake detection → Light → Sensitivity low to high
Medium sensitivity (default)

Light after sunset over 60 LUX is considered Awake

Low sensitivity

Light after sunset over 30 LUX is considered Awake

High sensitivity

Light after sunset over 120 LUX is considered Awake

The #dark tag is added when you have less than 30 lux for at least 90% of the night.
The #light tag is added when you have more than 60 lux for at least 33% of the night.

Light measurement also plays a role in Automatic sleep tracking.

2. Where to find it

Settings → Sleep tracking → Awake detection → Light