Thank you for downloading and using our app:
Twilight! French translation by Jeremy Del Grosso (Genetik57)
Do you have trouble falling asleep?
Are you a hyperactive child who plays on their smartphone or tablet before bed? Do you use your smartphone or tablet at the end of the evening? Twilight may be the solution for you!
Recent research suggests that exposure to blue light before sleeping can distort your natural (circadian) rhythm and cause an 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 between 460nm and 480nm, this range can suppress the production of melatonin – a hormone responsible for your healthy sleep-wake cycles.
In experimental scientific studies, it has been shown for the average person that reading on a smartphone or tablet two hours before sleeping can reduce by about an hour.
The Twilight app adapts to your device screen according to the time of day. It filters the blue spectrum on your smartphone or tablet after sunset and protects your eyes with a soft and pleasant red filter. The filter and intensity are smoothly adjusted to the solar cycle based on sunset and sunrise from your local time.
Examples of associated scientific research:
Amplitude and phase shift reduction of melatonin, cortisol, and other circadian rhythms after gradual progression 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 light in your bedroom before bedtime suppresses the appearance of melatonin and shortens the duration of melatonin in humans. Joshua J. Gooley, Kyle Chamberlain, Kurt A. Smith, Sat Bir S. Khalsa, Shantha MW 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
The effectiveness of a single sequence of intermittent light pulses can delay the phase of the circadian rhythm of 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 sleeping man. Kenneth P. Wright, Claude Gronfier Jeanne F. Duffy, Charles A. Czeisler 2009
The impact of timing of sleep and exposure to bright light can lead to attention deficit when working at night. Nayantara Santhi, Daniel Aeschbach, Todd S. Horowitz, Charles A. Czeisler 2008
Short-wavelength light sensitivity of circadian rhythms, pupil, and visual vacuum perception of the external retina in humans. 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 human circadian rhythm of melatonin to be reset by short wavelength light. Lockley SW, Brainard GC, Czeisler CA. 2003
Human circadian pacemaker nightlight sensitivity: reset and remove melatonin phase. Jamie M Zeitzer, Derk-Jan Dijk, Richard E Kronauer, N Emery Brown, Charles A Czeisler 2000
Phase-shifting human circadian rhythms influence how long you sleep, your social contact, and slight exposure to it. JF Duffy, RE Kronauer, CA Czeisler 1996
Exposure to light and dark can treat physiological poor adaptation to night work. Czeisler CA, Johnson MP, Duffy JF, Brown IN, Ronda JM, Kronauer RE. 1990