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Twilight: Blue light filter

Twilight: Blue light filter

Category

Size

Update

Health & Fitness

18.5 MB

May 01,2025

Application Description:

Are you struggling to fall asleep at night? Do your kids seem overly energetic after using their tablets before bedtime? If you find yourself using your smartphone or tablet late in the evening, or if you're sensitive to light during migraines, Twilight might be the solution you need!

Recent research indicates that exposure to blue light before sleep can disrupt your natural circadian rhythm, leading to difficulties in falling asleep. This is due to a photoreceptor in your eyes known as Melanopsin, which is sensitive to blue light in the 460-480nm range. Such exposure can suppress the production of Melatonin, a crucial hormone for maintaining healthy sleep-wake cycles. Studies have shown that individuals who read on a tablet or smartphone for a couple of hours before bed may experience a delay in sleep of about an hour.

The Twilight app adjusts your device's screen to the time of day by filtering out blue light after sunset and applying a soothing red filter to protect your eyes. The intensity of the filter smoothly adapts to the sun cycle, based on your local sunset and sunrise times. Twilight is also compatible with Wear OS devices, ensuring comprehensive protection.

For more detailed information, visit the Twilight documentation at http://twilight.urbandroid.org/doc/.

Twilight offers several benefits:

  1. Bed Reading: Twilight makes night reading more comfortable on the eyes and allows the screen backlight to be dimmed far below the standard settings.
  2. AMOLED Screens: Extensive testing on AMOLED screens over five years shows no signs of depletion or over-burning. With proper configuration, Twilight reduces light emission and distributes light more evenly, potentially extending your screen's lifespan.

For a deeper understanding of circadian rhythms and the role of melatonin, explore these resources:

Twilight requires certain permissions to function effectively:

  • Location: to determine your local sunset and sunrise times.
  • Running Apps: to pause Twilight in selected applications.
  • Write Settings: to adjust the screen backlight.
  • Network: to connect with smart lighting systems like Philips HUE to minimize household blue light exposure.

To filter notifications and the lock screen, Twilight may request access to the Accessibility Service. This service is used solely to enhance screen filtering and does not collect personal information. Learn more about this at https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/.

For Wear OS users, Twilight syncs the screen filter settings with your phone, controllable via a "Wear OS Tile."

For automation enthusiasts, Twilight can be integrated with Tasker and other automation apps. Find out more at https://sites.google.com/site/twilight4android/automation.

The effectiveness of Twilight is supported by several scientific studies:

  • 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)
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App Information
Version:

14.1

Size:

18.5 MB

OS:

Android 5.0+

Package Name

com.urbandroid.lux

Available on Google Pay
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