All calculations

How it works

Morning Light Exposure: Timing, Duration, and Gaps

See how daylight minutes, timing, circadian phase, bedtime, and available sensor data shape the Light Exposure and prescription views.

Light timing matters, but a phone or watch cannot see every photon that reached your eyes.

The light exposure result uses the inputs below.

What does morning light exposure mean?

The result turns several inputs into one clear view.

What goes into the calculation?

The app uses supported data and reads it in context.

What happens when data is missing?

No reading is better than a made-up reading.

What can this calculation not tell you?

The app can show a pattern, but it cannot prove a cause.

Your next step for light exposure

Compare like days before you judge the trend.

Related calculations

See light exposure in your own data

Body Insights shows the inputs and the change behind the result, so you can choose your next step.

See my light exposure