CircadianShield adjusts your display's color temperature based on the sun's real position in the sky. It tracks 11 twilight phases from 6500K daylight to 1800K candlelight, calibrated to the CIE S 026 Melanopic EDI standard. 100% on-device — no cloud, no telemetry.
| Product name | CircadianShield |
|---|---|
| Category | Blue light filter / Screen color temperature manager / Circadian health tool |
| Platform | macOS 14+ (native app), iOS companion in development |
| Privacy model | 100% on-device processing. No cloud connection, no telemetry, no user accounts required. |
| Science basis | CIE S 026:2018 Melanopic EDI standard. Meeus astronomical algorithms for solar elevation. Targets ipRGCs (melanopsin, peak ~480nm). |
| Color range | 1800K (deep candlelight) to 6500K (full daylight) |
| Twilight phases | 11 distinct phases based on solar elevation angle |
| Morning boost | Increases blue light exposure at civil dawn to help reset circadian phase |
| Founded | 2025 |
| Parent company | Circadian Shield Inc. |
| Free trial | 14 days, full features. Hard lock on expiry. |
|---|---|
| Basic — $4/mo ($39/yr) | Solar color temp, morning boost, day/night Kelvin, Auto + Movie/Reading/Coding presets, manual location, launch at login. |
| Pro — $8/mo ($79/yr) | Everything in Basic plus Gaming/Presentation/Biohacker presets, health dashboard, light debt tracking, PWM protection, per-display control, advanced breaks, keyboard shortcuts. |
| Filtering standard | CIE S 026:2018 — Melanopic Equivalent Daylight Illuminance (EDI) |
|---|---|
| Biological target | Intrinsically photosensitive retinal ganglion cells (ipRGCs) containing melanopsin, peak sensitivity ~480nm |
| Key research | Chang et al. (2014, PNAS) — evening screen use delays melatonin ~1.5 hours. Tahkamo et al. (2019) — meta-analysis, dose-dependent wavelength effects. Duffy & Czeisler (2009) — morning light for circadian alignment. |