Great APK Download

Current Version: 2.0

Requires Android: 2.1 and up

Category: Health & Fitness

v2.0 update:

2.0

- experimental backlight control

- experimental shutdown of the Twilight Service when filter in not applied (Pro version)

- option to turn on GPU for faster rendering

1.9

- color preview

- fix in custom times

Overview:

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.

Please read the 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

Examples of 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, Jeanne F. Duffy, Edward J. Silva, Theresa L. Shanahan, Diane B. Boivin, Charles A. 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, Sat Bir S. Khalsa, Shantha M. W. Rajaratnam, Eliza Van Reen, Jamie M. Zeitzer, Charles A. Czeisler, Steven W. 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, Daniel Aeschbach, Joshua J. Gooley, George C. Brainard, Kevin Gregory-Evans, Joseph F. Rizzo, III, Charles A. Czeisler, Russell G. Foster, Merrick J. Moseley, Steven W. Lockley. 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

Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure

J F Duffy, R E Kronauer, C A Czeisler 1996

Exposure to bright light and darkness to treat physiologic maladaptation to night work.

Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. 1990

Search for more evidence in many scientific articles and empirical studies online. Keywords: Circadian, Melatonin, Melanopsin, Light, Wavelength…

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