About this directory

Published studies of wearable light logger performance.

Literature checked 10 November 2026 · 28 studies · 29 device entries · 26 peer reviewed · 2 preprints · 0 conference paper

Using the directory

Browse devices by manufacturer, or sort by most validations, fewest validations or device name. Search for a device, author, title or DOI. The measurement and device-type filters narrow the results.

Each square represents one validation study. Orange hatching identifies developer involvement. Open a device to see its papers, study summaries and source links.

Device outputs shows confirmed photopic illuminance and melanopic EDI features. Examined in studies shows the measurements tested in the matching papers: photopic illuminance, melanopic EDI and angle dependence.

The collection

The directory brings together research publications and preprints that directly test wearable light loggers. Devices are grouped by manufacturer or research developer, with commercial models and research devices identified separately. LYS and LYS Button share one entry.

Papers were found through Europe PMC, searches for named devices and reference lists. Each entry links to the original publication, its DOI and PubMed where available.

Use Submit a validation to suggest a paper or correction by email.

Source and downloads

The site is built with Quarto from a shared literature inventory. The notebooks regenerate the directory, study inventory and downloadable records.

Study table (CSV) · Citations (BibTeX) · Directory notebook · About notebook · GitHub repository

Study inventory

Gemici et al. · 2026 · Preprint

Scene-based field validation of wearable light loggers ↗

Journal / server: arXiv
Devices: ActTrust2; ActLumus
Measurements: Illuminance; Melanopic EDI
Device-specific coverage: ActTrust2: Illuminance | ActLumus: Illuminance, Melanopic EDI
Setting: Field
Evidence type: Reference comparison
Reference: JETI Spectraval 1501 in Tübingen; Konica Minolta CL-500A in Izmir.
Protocol: Fixed tripod rig sampled 433 indoor/outdoor scenes across daylight, artificial and mixed lighting in Tübingen and Izmir. Bootstrap resampling assessed sampling requirements.
Findings: High association with reference measurements coexisted with systematic underestimation. Bias depended on the lighting condition and scene characteristics. Performance estimates stabilized at approximately 100 sampled scenes in this dataset.
Source passage: PDF pp. 6–7: Measurement setup; pp. 11–12: Results; Figure 2: A ActLumus mEDI, B ActLumus illuminance, C ActTrust2 illuminance.

DOI: 10.48550/arXiv.2606.20719

Kore et al. · 2026 · Peer reviewed

Evaluation of wearable light dosimeters for circadian lighting: spectral, spatial, photometric, melanopic, and thermal performance ↗

Journal / server: npj Biological Timing and Sleep
Devices: LYS Button; Blue Iris Speck v1.0; Actiwatch Spectrum Plus
Measurements: Angular response; Illuminance; Melanopic EDI
Device-specific coverage: LYS Button: Illuminance, Melanopic EDI, Angular response | Blue Iris Speck v1.0: Illuminance, Melanopic EDI, Angular response | Actiwatch Spectrum Plus: Illuminance, Angular response
Setting: Laboratory + field
Evidence type: Characterisation
Reference: Calibrated Gigahertz-Optik BTS256 spectroradiometer; cosine-law angular benchmark.
Protocol: Three units per model tested under controlled LEDs (0–570 lx) and partly cloudy daylight (42,000–78,000 lx), with separate angular and temperature tests.
Findings: Speck showed the strongest overall measurement agreement in this comparison. LYS Button overestimated low-light melanopic EDI. Actiwatch had substantial photometric variability. All models showed difficulties under high daylight levels.
Source passage: Results: Figures 2–3 (illuminance), 4–5 (Speck spectrum), 6 (melanopic EDI), 7 (angular response); Temperature dependence; Discussion limitations.