Twilight
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 Twilight1) 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 melatoninhttp://en.wikipedia.org/wiki/Melatoninhttp://en.wikipedia.org/wiki/Melanopsinhttp://en.wikipedia.org/wiki/Circadian_rhythmshttp://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.
Category : Health & Fitness
Reviews (27)
Does an excellent job. Despite the fact I've always had a lot of expectations towards this category of apps, this one provides unique and up-to-date options, such as filtering notifications and lock screen. I also like the fact tht it proposes a widget for the new notification bar (I'm on MIUI 12), although I would appreciate it if a long press on the widget could open the same menu as the one that is opened when I press the regular notification.
Great app! Sometimes the app turns out then turn on again especially when I'm on YouTube. But when I'm offline there's no problem. I really like it cos I can also decrease the luminosity lower than my phone's able to do it. It's useful when I use my phone in pitch black !
Been using Twilight for 3-4 years. Seriously cuts down on eye strain in the evening, and allows me to use my phone in the evening without worrying about messing with my sleep cycles. I like that I can set a timer, so I don't need to remember to turn off on/off. Only complaint is that it displays over my camera, so any photos you take with the filter enabled will have a red tint. But it's easy to switch it off for a quick second to take a picture , so it's not a big deal.
Good in theory, works well. However, it's making my screen wallpaper red, so may have to get rid of it. Edit: 5 stars. Devs kindly got in touch but I've been ill. Fault was solved (corrupted homescreen file). I have to say, I've used this app a lot over the years & it really is very good. Helps me massively with headaches (part of post covid problems).
I really like the app, but I can't rate 5 stars because I bought premium and there STILL doesn't seem to be a way to get rid of the little side-button that is always on your screen. I use the app to occasionally vamp up my phone's native blue light filter when I am reading in the dark, I don't need this button taking up real estate on my screen all day. Please address this issue and make a clear option to remove the quick toggle button, at least for pro-users.
Absolutely recommend this app, far better than all of the others I've tried. Biggest difference is that you can still use your phone normally when activated, even if your in a normally lit room because it actually changes the colours instead of just overlaying a darker filter. No ads and lots of useful functions. Big thanks to the developer, this app really helps
This such an eye saver. This, f.lux, and dark mode whenever possible are such a nice suite of utilities for doing anything on a screen at night. I'm impressed with all the possible customization. 3 ways to augment my phone's light output and 4 ways to schedule when Twilight is activated is more than I would have expected. It's a quiet, hands-off app made for one thing and it does it well.
App works well. Screen brightness control is far more granular than the standard control. Just two requests. 1. Can it also dim/disable the charging indicator led that turns on when the phone is plugged in? 2. Can screen dim take into account ambient light? There's no point dimming the screen if I'm in bright light.
The app won't give me a blueless home and lock screen. I don't think it's working properly. I've clicked the settings and they just won't work. My partner has the exact same phone as me and it works on hers but I don't understand why it won't work on mine. The home and lock screens still stay the same without turning to that nearly all red that she has on her phone. EDIT: the answer provided solved this issue :)
I've used and loved this app on my phones for years. No ads, customizable and totally free. Also it runs in the background with no annoying bars or icons on your screen. Just the best. Thank you to the developers for a truly great app!
Someone somewhere suggested this app and I use it religiously. I adore that you can turn your screen brightness down way more than phone settings. And that it's extremely easy to click on and off. And that it doesn't HAVE to be on a schedule. It does show up in my screencaps though. And it turns on randomly. But overall I think I'll continue to use this until the developers shut it down. I'm going to buy the pro to support them. Seriously, try it.
Perfect, when it works. 3 or 4 nights a week I realise hours after my set schedule that it never turned on. No matter how many times check permissions, it turns off all the time. I let it "draw over apps", but this means I can't do things like use Messenger or close pop ups in my browser. I know system level apps are hard, and none of the blue light apps can do it well, but please keep improving this!
Turns on whenever it wants to. Disregards filters that you might set within the app. Interferes with every other app that's running at the time, ie, they all turn red. Annoying if you're watching a movie/TV show. Why have settings so that intensity, times, etc can be adjusted if they don't work? Frustrating!
I've used Twilight for years. I'm 100% satisfied with its use as a blue light filter. It's extremely easy to use and customize. No ads. I can definitely tell that it helps eye fatigue and helps me sleep better at night. HIGHLY recommend
I've been using Twilight for years and I wouldn't have a phone without it! People are often surprised by my reddish phone at night, but I don't even notice it anymore. I do notice when I see someone else's phone at night without Twilight and it hurts my eyes! I'm an insomniac so I try to be careful about anything that might disturb my sleep even more. Thanks!
Loved it. An Amazing app that significantly lowered stress on my eyes. Perfectly blends in with the screen. I do think Backlight is a little issue. Please look into it.
I love this light filter. I've tried 2 or 3 apps in the past but had technical issues so uninstalled them. This app is easy to use and seems to work seamlessly, it's a nice warm red colour also which you can adjust to your liking. It gives hints as well a long the way to help you make the right choices when choosing certain intensity levels on the filter. I would recommend this app to anyone who uses their phone a lot at night. I work night shifts so comes in very handy as use my phone at work.
Update in 2022. App no longer crashes which is good. That's it. This is another update from FEB 20 2020 The only problem with this app is that it keeps deactivating on me everytime I use it. When I turn up the brightness up a bit it starts to bug out. Please fix it. Other than that everything is great. Also helps my retina whenever I watch YouTube at night. Just fix that one bug. The bug where it stops working then works again is still there guys. This is an update from Oct. 2019.
Excellent! It makes a real difference on the eyes and on the sleep cues to the brain. Even the free strings are quite adequate to automatically disable it by app you run, and set it to turn itself on and off by time of day. Set & forget, or pause it manually, as you prefer.
Great app. My baby is really sensitive to light and qill wake up with any change. This app allows me to use my phone whilst hes asleep on me in a dark room. It also takes away eye strain and I can use myvphine right before bed, without it making it difficult for me to fall asleep, something that's usually a problem for me. You can adjust the intensity of the filter and set it to automatically turn on at certain times, or have it on all the time. Well done to the developers
Works as expected. Very useful customizable screen settings including color temperature down to deep red. One minor bug with Android 12 is "display over other apps" interferes with the Google Play Store. To correct pause Twilight when installing or updating apps. A side benefit is Twilight can be used to prevent unauthorized users from installing apps via the Play Store.
Love using this app to set up different screen filters at different times. Bought the premium version. Only complaint is that there is no way to export profiles to quickly move setting through multiple devices. Best android screen filter app hands down.
I liked the functionality, but I had to disable the app. I allowed all permissions and followed instructions but several other apps stopped functioning properly because of the overlay (e.g. Spotify, Google Apps, games). Maybe I'll experiment more later but had to get away from those problems first. Update: Pausing unfortunately didn't help. E.g. in Spotify some buttons like "All episodes" stopped working. I wonder if that is considered a secure button too.
Still not fully happy anymore. Finding good balance is difficult. Been using app for years now & liked it very much. After 3 updates I've been having trouble using the phones camera, the screen blinks slightly while using other apps & worst of all. I can't update ANYTHING through the PlayStore. Unless I turn off app. I'm patient & figured they'd fix the MAJOR ISSUE. Willing to wait a while, see if adjustments make it OK, uninstaling if the problem gets worse. Sony Xperia XZ2 Premium Android 10.
I love this app, and the upgrade is so worth it. it's seamless to use, and easy to pause if I want to see unadjusted colors for watching a video or something similar. I have it set so sync with the sunrise and set, and it helps significantly with my insomnia, as the screens I use most often all have Twilight or F.lux installed, depending on which is available
Turns on early/doesn't turn on at the time specified in settings. It does not stop the filter when settings are changed, when you restart phone, when you press pause, or if you use the stop function.
Effective reduction of blue component of light, colour temperature can be set manually. After experimenting with the settings in Android and in Twilight it now starts on booting. There is a delay but it's not a problem. Very pleased with blue light reduction, it makes the tablet much easier on the eyes.