Light is the number-one signal that sets your biological clock. Received in the morning, it advances and stabilises the circadian rhythm; received late at night, it shifts it. Light therapy delivers calibrated light at the right time to support that rhythm.
The internal clock and light
Specialised retinal cells (melanopsin) inform the brain of light levels and synchronise the central clock. When this signal is weak or mistimed (winter, indoor work, jet lag), the rhythm gets disrupted: night-time awakenings, low morning energy.
Light therapy has a moderate effect on sleep parameters (effect size g ≈ 0.47), notably a reduction in night-time awakenings (~11 minutes). Sleep-onset latency, however, is not consistently improved — let's be honest.
Key data
What it targets — honestly
- Yes: circadian resynchronisation, morning alertness, fewer night-time awakenings.
- Nuance: a moderate effect, variable between people; not a miracle sleep fix.
- Caution: medical advice in case of retinal disease, photosensitising medication or bipolar disorder.
We build light therapy into your morning routine, in a portable format, as part of circadian resynchronisation paired with sleep tracking.