In short
Twilight is a free Android app from Urbandroid Team. It is suitable for developers and friends. It is a great way to save eyes.
Highlights
My only complaint is it applies to any Android wear device as well
Nice application doing exactly what is supposed to do
Inform myself and do everything useful apps allow me to do nowadays
I do a lot of work at night and this is a definite plus
Good amount of customization options
Great app which runs without problems under Android 4
This app allows me to use my phone more without concern
The most beneficial app I have on my phone
This app was perfect on my last phone
Works well and now I'm able to sleep after reading in bed
And there is no way to disable the effect on Android wear only
Only when I type the whole screen sort of flickers
That was supposed to turn on and off automatically
Partial screen is not filtered
It stops working within few minutes
Who actually responds to crash reports
Apparently this is a known issue with Huawei phones
Drains battery excessively
Why does the app keep turning off every few minutes
Now is producing overlay error
Description
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? 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. 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 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, Daniel Aeschbach & 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, 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 & Co 2000 For a desktop alternative, try RedShift (Linux) or on Windows the app which has no relation to this project whatsoever, whose name cannot be said aloud or whispered as it is a Trademark, lets call it Lord Voldemort of the blue light flux filtering apps.Guessed it? Let us know in the comments.
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