Twilight: Blue light filter 13.8

Are you struggling to fall asleep? Do your children become hyperactive when playing with tablets before bedtime? Do you use your smartphone or tablet late in the evening? Are you sensitive to light during migraines?

If so, Twilight may be the 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 a photoreceptor in your eyes called Melanopsin, which is sensitive to a specific range of blue light. This blue light can suppress the production of melatonin, a hormone responsible for regulating sleep-wake cycles.

In experimental studies, it has been shown that an average person reading on a tablet or smartphone for a couple of hours before bedtime may experience a delay in their sleep by about an hour.

The Twilight app is designed to adapt your device screen to the time of day. It filters the blue light emitted by your phone or tablet after sunset and replaces it with a soft and pleasant red filter, which helps protect your eyes. The intensity of the filter adjusts smoothly based on your local sunset and sunrise times.

You can also use Twilight on your Wear OS device.

For more information, see the documentation: http://twilight.urbandroid.org/doc/

Here are some additional benefits of using Twilight:

1. Bed Reading: Twilight provides a more comfortable reading experience at night by lowering the screen backlight beyond the capabilities of standard backlit controls.
2. AMOLED screens: The app has been tested on AMOLED screens for 5 years without any signs of depletion or over-burning. Properly configured, Twilight reduces light emissions and promotes equal light distribution, potentially extending the lifespan of your AMOLED screen.

If you are interested in learning more about the circadian rhythm and the role of melatonin, you can find additional information at the following links:

• Melatonin - Wikipedia
• Melanopsin - Wikipedia
• Circadian Rhythms - Wikipedia
• Circadian Rhythm Disorder - Wikipedia

The app requires certain permissions:

• Location access - to determine your local sunset/sunrise times
• Running apps access - to stop Twilight in selected apps
• Write settings access - to adjust the backlight settings
• Network access - to control smart lighting (Philips HUE) to limit blue light exposure in your household

In order to filter your notifications and lock screen, Twilight may prompt you to enable Twilight Accessibility Service. This service is only used to enhance screen filtering and does not collect personal information. For more information, please read the privacy policy: https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/

If you have a Wear OS device, Twilight can sync your screen with your phone's filter settings. You can control the filtering from a "Wear OS Tile".

If you want to automate the app with Tasker or other automation tools, additional information can be found at: https://sites.google.com/site/twilight4android/automation

For further reading, here are some related scientific research papers:

• 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, Kenneth P. Wright, et al. 2009
• Intrinsic Period and Light Intensity Determine the Phase Relationship between Melatonin and Sleep in Humans - Kenneth P. Wright, Claude Gronfier, 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