What it’s for
- Evening wind-down
- Managing evening light exposure
Brightness, spectrum and duration all matter; bulb colour alone does not define the exposure.
Reducing light intensity in the evening as part of preparing for sleep.
Purpose, evidence and practical considerations.
Brightness, spectrum and duration all matter; bulb colour alone does not define the exposure.
Evening light affects circadian timing. Studies of reducing short-wavelength light have mixed sleep results, so a specific lamp colour is not a proven insomnia treatment.
Confidence: moderate
Dim light can increase fall and task-safety risk; retain enough illumination for safe movement. Persistent insomnia or circadian disorders warrant assessment rather than reliance on bulb colour alone.
Retinal light exposure, especially at short wavelengths and sufficient intensity, suppresses melatonin and shifts circadian timing. Spectrum, brightness, distance, duration and individual sensitivity all matter; a red bulb label alone does not define exposure.
Regulatory status: sleep-hygiene and circadian-light practice
The evidence on this page does not automatically apply to:
How people use it, with their schedules, context and original sources.
nightly · evening
He dims the lights as he winds down for bed.
Session and schedule patterns reported in public protocols; these are observations, not instructions. Private and hidden usage is excluded.
These share a protocol with this intervention. This does not establish that they work together or are suitable alternatives.
2 hours before sleep