Are you struggling to fall asleep? Do your children become overly active when using tablets before bedtime? If you frequently use your smartphone or tablet in the evening, or if you're sensitive to light during migraines, Twilight might be the solution you need.
Recent studies indicate that exposure to blue light before sleep can disrupt your natural circadian rhythm, making it harder to fall asleep. The culprit is a photoreceptor in your eyes known as Melanopsin, which is sensitive to blue light in the 460-480nm range. This light can suppress the production of Melatonin, a hormone crucial for maintaining healthy sleep-wake cycles. Scientific experiments have shown that reading on a tablet or smartphone for a couple of hours before bed can delay sleep by about an hour.
The Twilight app adjusts your device's screen to match the time of day. It filters out the blue light emitted by your phone or tablet after sunset, protecting your eyes with a soothing red filter. The intensity of the filter smoothly adjusts based on your local sunset and sunrise times, ensuring a seamless transition.
Twilight is also compatible with Wear OS devices, extending its benefits to your smartwatch.
Documentation
For more detailed information, visit http://twilight.urbandroid.org/doc/.
Get More from Twilight
- Bed Reading: Twilight enhances the night reading experience by providing a more pleasant visual setting. It can dim the screen backlight far below the standard controls, making it easier on your eyes.
- AMOLED Screens: Our tests on AMOLED screens over five years show no signs of depletion or over-burning. Properly configured, Twilight reduces light emission and provides a more even light distribution, which may even extend the lifespan of your AMOLED screen.
Basics on Circadian Rhythm and the Role of Melatonin
For further reading on these topics, check out these resources:
Permissions
- Location: To determine your local sunset and sunrise times.
- Running Apps: To disable Twilight in selected applications.
- Write Settings: To adjust the screen backlight.
- Network: To access smart lighting systems like Philips HUE, helping to shield your household from blue light.
Accessibility Service
To filter notifications and the lock screen, Twilight may request the activation of its Accessibility Service. This service is used solely to enhance screen filtering and does not collect any personal data. Learn more about this at https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/.
Wear OS
Twilight synchronizes your Wear OS screen with your phone's filter settings, and you can control the filtering directly from a "Wear OS Tile".
Automation (Tasker or Other)
For automation options, visit https://sites.google.com/site/twilight4android/automation.
Related Scientific Research
- Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans - Derk-Jan Dijk, & Co, 2012
- Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans - Joshua J. Gooley, Kyle Chamberlain, Kurt A. Smith & Co, 2011
- Effect of Light on Human Circadian Physiology - Jeanne F. Duffy, Charles A. Czeisler, 2009
- Efficacy of a single sequence of intermittent bright light pulses for delaying circadian phase in humans - Claude Gronfier, Kenneth P. Wright, & Co, 2009
- Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans - Kenneth P. Wright, Claude Gronfier & Co, 2009
- The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work - Nayantara Santhi & Co, 2008
- Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina - Farhan H. Zaidi & Co, 2007
