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. See
references below..
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/
Wear OS
Twilight also syncs your Wear OS screen with your phone’s filter
settings. You can control filtering from a “Wear OS Tile”.
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