Do you struggle with falling asleep? Are your children overly energetic after using tablets before bedtime? If you're using your smartphone or tablet late in the evening or if you're sensitive to light during migraines, Twilight might be the perfect solution for you.
Recent research indicates that exposure to blue light before sleep can disrupt your natural circadian rhythm, leading to difficulties in falling 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 Melatonin production, a hormone crucial for maintaining healthy sleep-wake cycles. Studies have shown that an average person who reads on a tablet or smartphone for a couple of hours before bed may experience a delay in sleep by about an hour. For further reading, see the references listed below.
The Twilight app adjusts your device's screen according to the time of day. It filters out the blue light emitted by your phone or tablet after sunset and protects your eyes with a soft, pleasant red filter. The intensity of the filter smoothly adjusts based on your local sunset and sunrise times.
Twilight is also compatible with Wear OS devices.
Documentation
http://twilight.urbandroid.org/doc/
Get More from Twilight
1) Bed Reading: Twilight provides a more eye-friendly experience for night reading. It can lower the screen backlight far below what's possible with standard backlight controls.
2) AMOLED Screens: Extensive testing on AMOLED screens over five years shows no signs of depletion or over-burning. Properly configured, Twilight reduces light emission and provides a more even light distribution, which may extend your AMOLED screen's lifespan.
Basics on Circadian Rhythm and the Role of Melatonin
http://en.wikipedia.org/wiki/Melatonin
http://en.wikipedia.org/wiki/Melanopsin
http://en.wikipedia.org/wiki/Circadian_rhythms
http://en.wikipedia.org/wiki/Circadian_rhythm_disorder
Permissions
- Location: To determine your current sunset and sunrise times.
- Running Apps: To disable Twilight in selected apps.
- Write Settings: To adjust the backlight.
- Network: To access smart light systems like Philips HUE, shielding your household from blue light.
Accessibility Service
To filter notifications and lock screens, Twilight may request enabling its Accessibility Service. This service is used solely to enhance screen filtering and does not collect any personal information. Learn more at https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/.
Wear OS
Twilight syncs your Wear OS screen with your phone's filter settings, which you can control via a "Wear OS Tile".
Automation (Tasker or Other)
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
