Twilight

Twilight


Are you having troubles to fall 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? 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 blue spectrum on 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.

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 2.5 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

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, Czeisler 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, Richard E. Kronauer, Megan E. Jewett, Charles A. Czeisler 2009

Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans Kenneth P. Wright, Claude Gronfier, Jeanne F. Duffy, Charles A. Czeisler 2009

The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work Nayantara Santhi, Daniel Aeschbach, Todd S. Horowitz, Charles A. Czeisler 2008

Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina Farhan H. Zaidi, Joseph T. Hull, Stuart N. Peirson, Katharina Wulff & Co, 2007

High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Lockley SW, Brainard GC, Czeisler CA. 2003

Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression Jamie M Zeitzer, Derk-Jan Dijk, Richard E Kronauer, Emery N Brown, Charles A Czeisler 2000

More evidence in scientific studies online, keywords: Circadian, Melatonin, Melanopsin, Light, Wavelength, Insomnia..

Similar to f.lux on Windows or Red Shift on Linux.

Recent changes:
3.6
- Material redesign
- Menu drawer
3.5
- option to cover also the translucent navigation bar on KitKat
- Farsi translation (many thanks to Farzad)
- option to enable civil sunset is back
- Fix for rare start up crash
3.4
-more high res
- fix for civil sunrise times shown instead of official (only a presentational problem - filter is based on official anyway)
3.3
- filter time modes - Always/Sun/Alarm/Custom
- Custom mode now available in free version
- Visual indicator of filter times...
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Free
92
4.6
User ratings
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Installs
500,000+
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1
File size
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About Twilight
Are you having troubles to fall 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? 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 blue spectrum on 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.

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 2.5 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

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, Czeisler 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, Richard E. Kronauer, Megan E. Jewett, Charles A. Czeisler 2009

Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans Kenneth P. Wright, Claude Gronfier, Jeanne F. Duffy, Charles A. Czeisler 2009

The Impact of Sleep Timing and Bright Light Exposure on Attentional Impairment during Night Work Nayantara Santhi, Daniel Aeschbach, Todd S. Horowitz, Charles A. Czeisler 2008

Short-Wavelength Light Sensitivity of Circadian, Pupillary, and Visual Awareness in Humans Lacking an Outer Retina Farhan H. Zaidi, Joseph T. Hull, Stuart N. Peirson, Katharina Wulff & Co, 2007

High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light. Lockley SW, Brainard GC, Czeisler CA. 2003

Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression Jamie M Zeitzer, Derk-Jan Dijk, Richard E Kronauer, Emery N Brown, Charles A Czeisler 2000

More evidence in scientific studies online, keywords: Circadian, Melatonin, Melanopsin, Light, Wavelength, Insomnia..

Similar to f.lux on Windows or Red Shift on Linux.

Recent changes:
3.6
- Material redesign
- Menu drawer
3.5
- option to cover also the translucent navigation bar on KitKat
- Farsi translation (many thanks to Farzad)
- option to enable civil sunset is back
- Fix for rare start up crash
3.4
-more high res
- fix for civil sunrise times shown instead of official (only a presentational problem - filter is based on official anyway)
3.3
- filter time modes - Always/Sun/Alarm/Custom
- Custom mode now available in free version
- Visual indicator of filter times...

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User reviews of Twilight
Fell asleep fast. Woke up with a hole in the wall and my dog is now afraid of me.
Apr 9, 2013
Android Market Comments
A Google User
6 hours ago
Works Great Changes the colour scheme on my phone at night. Excellent, even when reading books. I'm also using f.lux for Windows, to keep my laptop from keeping me awake. Just bought the Pro version. This is a brilliant app!
A Google User
7 hours ago
Great app Eases eye strain at night
A Google User
9 hours ago
Nice... It took me a while to get it dialed in the way I like it but I did. Great app...
A Google User
9 hours ago
Stable The only app of this kind that works consistently. Lacks some of the nice to have filters of the others, but is far more reliable in not jolting you with a bright screen in the wee hours.
A Google User
9 hours ago
Stops/crashes/Turns off after some minutes