Home Apps Health & Fitness Twilight: Blue light filter
Twilight: Blue light filter

Twilight: Blue light filter Rate : 4.4

Download
Application Description

Are you struggling to fall asleep at night? Do your children become overly energetic after using tablets before bedtime? If you're using smartphones or tablets in the evening or suffer from light sensitivity during migraines, the Twilight app could be the perfect solution for you.

Recent research indicates that exposure to blue light before sleep can disrupt your natural circadian rhythm, making it difficult to fall asleep. This is due to the 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 reading on a tablet or smartphone for a few hours before bed can delay sleep by approximately an hour.

The Twilight app adjusts your device's screen based on the time of day, filtering out blue light after sunset and applying a soothing red filter to protect your eyes. The intensity of the filter is smoothly adjusted according to your local sunset and sunrise times, ensuring a comfortable viewing experience.

Twilight is also compatible with Wear OS devices, extending its benefits to your smartwatch.

Documentation

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

Get More from Twilight

1) Bedtime Reading: Twilight enhances the reading experience at night by applying a more eye-friendly filter, capable of dimming the screen far beyond the standard backlight controls.

2) AMOLED Screens: Our tests show that using Twilight on AMOLED screens for 5 years shows no signs of depletion or over-burning. Proper configuration reduces light emission and promotes even light distribution, potentially extending your screen's lifespan.

Basics on Circadian Rhythm and Melatonin

Learn more about the science behind sleep and light sensitivity:

Permissions

Twilight requires the following permissions to function effectively:

  • Location - to determine your local sunset and sunrise times.
  • Running Apps - to disable Twilight in specific apps.
  • Write Settings - to adjust the backlight.
  • Network - to connect with smart lighting systems like Philips HUE, protecting your home from blue light.

Accessibility Service

To extend filtering to notifications and lock screens, Twilight may request the use of the Accessibility Service. This service is used solely to enhance screen filtering and does not collect any personal data. For more information, visit https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/.

Wear OS

Twilight synchronizes with your Wear OS device, applying the same filter settings as your phone. You can manage these settings directly from a "Wear OS Tile".

Automation (Tasker or Other)

For advanced users looking to automate Twilight, visit https://sites.google.com/site/twilight4android/automation.

Related Scientific Research

Explore the scientific backing for Twilight's effectiveness:

  • 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 et al., 2012
  • Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans, Joshua J. Gooley et al., 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 et al., 2009
  • Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans, Kenneth P. Wright et al., 2009
  • The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work, Nayantara Santhi et al., 2008
  • Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina, Farhan H. Zaidi et al., 2007
Latest Articles More
  • Roblox 99 Nights: Beginner Survival Guide

    Roblox's 99 Nights in the Forest blends survival mechanics, exploration, and subtle horror elements into one of the platform's most distinctive experiences. While new players may initially struggle with resource management and enemy encounters, maste

    Dec 30,2025
  • Seven Knights Re:BIRTH Global Pre-Reg Rolls Out

    Netmarble's Beloved RPG Returns With Fresh EnhancementsNetmarble breathes new life into one of its most acclaimed mobile RPG franchises with Seven Knights Re:BIRTH, now open for global pre-registration. The developer has unveiled the first glimpse of

    Dec 30,2025
  • Elden Ring Player Hits Relic Storage Limit

    Relics are powerful items that give your Nightfarer a significant advantage during each run in Elden Ring Nightreign. However, there's a limit to the number you can store in your hideaway.Earlier today, a user on the r/Nightreign subreddit shared a s

    Dec 30,2025
  • Patch Quest Launches on Mobile via Crunchyroll Game Vault

    Crunchyroll Game Vault has unveiled its latest title, Patch Quest, offering players a thrilling adventure on a monster-infested island with ancient ruins to explore. The game features cooperative multiplayer and a unique monster-taming system where c

    Dec 30,2025
  • Nintendo Switch 2, Mario Kart World: High Price Explained

    The latest Nintendo Direct finally revealed pricing details for the upcoming Switch 2, answering burning questions about launch titles and release dates. While the showcase delivered exciting announcements, several price points raised eyebrows across

    Dec 30,2025
  • Ridley Scott on Alien Franchise: It's Time to Move On

    Legendary director Ridley Scott has signaled his departure from the Alien franchise, stating: "I believe I've done all I can."The 87-year-old English filmmaker, who helmed the groundbreaking 1979 sci-fi horror Alien before revitalizing the series wit

    Dec 27,2025