CortexLit

CortexLit tool · Sleep · Runs offline · No account

Bedroom Light Audit

List the light sources in your bedroom and evening, rank them by when they are on, and print the two worth removing first.

← Back to the article · See the evidence

This tool gives general information based on the research summarised in Light in the Bedroom at Night: What the Studies Show. It is not a medical device, does not diagnose, and does not replace advice from your clinician.

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Free (this page)
  • full audit of bedroom and evening light sources
  • the two actions to try first
  • text export and print
  • all citations and cautions


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  • calendar (.ics) evening dimming reminders
  • unlimited share images
  • share card without the 'Made with CortexLit' footer


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Free tier: 1 share image per result.






Commercial disclosure: optional paid Plus tier; all evidence, cautions and the main result are free. No affiliate links, no sponsors.







What this is based on


Every output names at least one verified PubMed source. Identifiers were verified on 2026-10-11 in an earlier batch and carried over into this build; they were not re-queried here, and no retraction database was checked. Verification was at abstract level.


Mason 2022
Mason IC, Grimaldi D, Reid KJ, et al. Light exposure during sleep impairs cardiometabolic function. Proc Natl Acad Sci U S A. 2022;119(12):e2113290119. doi:10.1073/pnas.2113290119. PMID: 35286195.
PMID 35286195 · mechanistic human lab · weight 0.2 · abstract level
Gooley 2011
Gooley JJ, Chamberlain K, Smith KA, et al. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. J Clin Endocrinol Metab. 2011;96(3):E463-E472.
PMID 21193540 · randomized controlled trial · weight 0.8 · abstract level
Hu 2010
Hu RF, Jiang XY, Zeng YM, et al. Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environment. Crit Care. 2010;14(2):R66. doi:10.1186/cc8965. PMID: 20398302.
PMID 20398302 · non randomized trial · weight 0.5 · abstract level


Limits: The audit counts sources you report; it does not measure lux, spectrum or timing. Priority order is an editorial judgement based on when each source is on, not a measured effect size.







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