Twilight APK

Struggling to fall asleep? Kids too hyperactive before bedtime with their tablet? Using your smartphone or tablet at night affecting your sleep? Sensitive to light during migraines? Look no further than the Twilight app! Research indicates that blue light exposure can distort your natural sleep rhythm and make it difficult to fall asleep. The app works by adapting your device screen to the time of day, filtering the blue light emitted by your device with a gentle red filter after sunset, and smoothing the filter intensity based on your local sunrise and sunset times. This helps protect your eyes and makes your device more pleasant to use at night. Additionally, the app offers Bed Reading, which reduces the screen backlight, and supports AMOLED screens, which can prolong screen life. With references to scientific studies supporting the app's benefits, this app is perfect for anyone seeking healthier sleep.

What is the Twilight app?

The Twilight app filters the blue light emitted by your phone or tablet after sunset and protects your eyes with a soft and pleasant red filter. It adapts to the time of day and adjusts the filter intensity based on your local sunset and sunrise times.

Why should I use the Twilight app?

Recent studies suggest that exposure to blue light before sleep may distort your natural circadian rhythm and cause difficulty falling asleep. The Twilight app can help filter out blue light and help you fall asleep easier.

How does the Twilight app work?

The app uses a red filter to adjust the light emitted by your device screen based on your local sunset and sunrise times. This helps protect your eyes from blue light, which studies suggest can impair sleep.

Can I use the Twilight app on my smartwatch?

Yes, Twilight is also compatible with Wear OS devices.

What kind of screens can I use Twilight on?

Twilight has been tested on AMOLED screens for 5 years without any signs of depletion or over-burning. The app causes less light emission and more equal light distribution, which can actually increase your AMOLED screen's lifespan.

What kind of permissions does the Twilight app require?

The app requires permission to access your location to find out your current sunset and sunrise times, running apps to stop Twilight in selected apps, write settings to adjust your device's back-light, and network access for smartlight (Philips HUE) to protect your household light from blue light exposure.

How does the Accessibility Service work?

To filter your notifications and lock screen, the app may ask for enabling the Twilight Accessibility Service. The app only uses this service to filter your screen and does not collect any personal information.

Is there any related scientific research available?

Yes, there are many scientific research studies related to circadian rhythm, melatonin, and blue light exposure. Some related studies include "Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans" and "High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light."

Are you having trouble falling asleep? Are your kids hyperactive when playing with the tablet before bed time? Are you using your smart phone or tablet in the late evening? Are you sensitive to light during migraine?
Twilight may be a solution for you!

Recent research suggests that exposure to blue light before sleep may distort your natural (circadian) rhythm and cause inability to fall asleep.

The cause is the photoreceptor in your eyes, called Melanopsin. This receptor is sensitive to a narrow band of blue light in the 460-480nm range which may suppress Melatonin production

- a hormone responsible for your healthy sleep-wake cycles.

In experimental scientific studies it has been shown an average person reading on a tablet or smart phone for a couple of hours before bed time may find their sleep delayed by about an hour.

The Twilight app makes your device screen adapt to the time of the day. It filters the flux of blue light emitted by your phone or tablet after sunset and protects your eyes with a soft and pleasant red filter. The filter intensity is smoothly adjusted to the sun cycle based on your local sunset and sunrise times.

You can also use Twilight on your Wear OS device.

Documentation
http://twilight.urbandroid.org/doc/

Get more from Twilight
1) Bed reading: Twilight is more pleasant on the eyes for night reading. Especially as it is able to lower the screen backlight far below the ability of the backligt controls on your screen
2) AMOLED screens: We have tested Twilight on an AMOLED screen for 5 years without any sign of depletion or over-burning. If properly configured Twilight causes less light emission (by enabling dimming) with more equal light distribution (dark areas of the screen such as the status bar get tinted). This may in fact increase your AMOLED screen life time.

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 find out your current sunset/surise times
- running apps - to stop Twilight in selected apps
- write settings - to set back-light
- network - access smartlight (Philips HUE) to shield you household light from blue

Accessibility Service
In order to filter also your notifications and lock screen the app may ask for enabling Twilight Accessibility Service. The app uses this service only to better filter your screen and does not collect any personal information. Please read more about this at https://twilight.urbandroid.org/is-twilights-accessibility-service-a-thread-to-my-privacy/

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
High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Lockley SW & Co. 2003

To install "Twilight" APK on your computer, you will first need to download an Android emulator such as Bluestacks or NoxPlayer. Once you have installed an emulator, follow these steps:

1. Download the "Twilight" APK file from a trusted source.

2. Open the emulator and navigate to the "Install APK" option.

3. Select the "Twilight" APK file you downloaded and click install.

4. Wait for the installation process to complete.

5. Once the installation is complete, you can open the app and start using it on your computer.