Measurement & Disclaimer
This page explains the limits of JoyLights’ measurements for users and App Store review.
1. What this app is
JoyLights uses the iPhone rear camera and system exposure/white-balance signals to estimate illuminance (lux), correlated color temperature (CCT), and light flicker trends. Results are for everyday eye-care habits—not a certified meter, engineering instrument, or medical device.
2. Illuminance (lux)
- Illuminance is estimated from aperture, shutter, ISO and related parameters with an empirical calibration.
- Phone model, lens, surface reflectance, and aiming angle all affect readings.
- Aim at a matte wall or desk, hold steady 2–3 seconds; do not aim at screens, bare LEDs, or mirrors.
- Changing the surface or angle can change the reading—that is expected.
- Values may differ from a calibrated lux meter and must not be used for compliance, occupational hygiene, or safety certification.
3. Correlated color temperature (CCT)
CCT (in kelvin, K) is estimated from camera white-balance related data and can shift with mixed lighting or colored walls. Night “cool CCT” tips are lifestyle guidance only.
4. Flicker
- Observation uses a short exposure (~1/1000s) to reveal rolling-shutter stripes.
- Percent flicker is an estimate from luminance variation.
- Results depend on frame rate, lamp type, distance, hand shake, and sensor. They cannot replace a flicker meter, lamp test report, or medical/safety advice.
5. Disclaimer
- Readings, guidance, and eye-care reminders are for personal everyday reference only.
- The developer is not liable for losses from relying solely on this app.
- Seek an eye-care professional if you have vision or eye-health symptoms.
6. Contact
Email: superdaddy2026@163.com
Document hub: https://legal.macrosss.com/joylights/