Posts Tagged ‘eye strain’

How to stop REDSHIFT night light brightness and color saturation eye strain protection on GNU / Linux

Tuesday, August 7th, 2018

Reading Time: 3minutes

You know on most operating systems such as Windows 8 / 10 ,  Mac OS X as well as  GNU / Linux / BSDs (FreeBSD) etc. with graphical environments such as  GNOME / KDE etc. , there is this default functionality nowadays that is helping to reduce eye strain and improve night sleep by modifying the light and brightness as well as coloring eminated by the monitor. 

On Windows this technology is called Night Light and is easily enabled by nagivating through menus:


Start > Settings  > System > Display > Night light > Night light settings.


Windows 10 Night Time settings shot

On GNU / Linux and BSD-es the eye strain application that comes preinstalled by default on most distributions is redshift – for more what is redshift check out my previous article get more peaceful night sleep on Ubuntu, Mint and Xubuntu Linux.

There is also the alternative to use F.lux (which by the way is used to prevent eye strain on Mac OS X and was the program of choice to prevent eye strain in older Windows versions)

Even though Night Light / and redshift monitor color warmth change is often mostly useful and have a positive impact improving sleep as well removes eye strain on Linux my experience with it is not too positive as it changes the monitor color gamma and makes it often quite reddish and annoying even through a normal day and not only night time.
This makes the work experience on the computer not pleasurable thus just removing it for me and I guess for many would be a must.

Assuming that you have installed Free software OS such as Linux with redshift (note that on on older releases of Deb and RPM package based distributions: you will have to manually install it with something like:)

On Debian based distros with:

root@debian:~# apt-get install –yes redshift redshift-gtk

On RPM Fedora / Cent OS, Redhat Enterprise Linux etc. with a command like:


[root@fedora]# yum install –yes redshift redshift-gtk


Redshift settings on Linux with KDE GUI

So in order to remove redshift it completely from Linux which usually on most GNU / Linux distros is running as a default process







1. * Make sure you kill all processes called redshift and redshift-gtk

to do so check processes with same name and KILL 'EM ALL!:

root@linux:~# ps aux|grep -i redshift
hipo     44058  2.8  0.5 620980 42340 pts/2    Sl+  20:33   0:00 /usr/bin/python3 /usr/bin/redshift-gtk
hipo     44059  0.1  0.0 295712  6476 pts/2    Sl+  20:33   0:00 /usr/bin/redshift -v

root@linux:~# kill -9 44058 44059

2. * Set the color temperature of the Monitor / Screen back to 6500K (this can be done either by the button menu that most screens have)

or manually with redshift itself by executing command:


root@linux:~# redshift -O 6500

As the screen is back to normal color gamma, its now time to completely remove redshift in order to prevent it to mess up with your monitor colors, on next PC boot or on Gnome / Mate whatever UI used session logout.

To do so issue commands:



root@linux:~# dpkg –purge redshift redshift-gtk
(Reading database … 516053 files and directories currently installed.)
Removing redshift-gtk (1.11-1) …
Purging configuration files for redshift-gtk (1.11-1) …
Removing redshift (1.11-1) …
Processing triggers for man-db (2.8.3-2) …
Processing triggers for hicolor-icon-theme (0.17-2) …
Processing triggers for mime-support (3.61) …
Processing triggers for gnome-menus (3.13.3-11) …
Processing triggers for desktop-file-utils (0.23-3) …
Processing triggers for menu (2.1.47+b1) …

3. Enjoy normal colors on your monitor  Goodbye Forever REDSHIFT, goodbuy dark crappy Screen during the day. Hello normal Screen light !!! 🙂

Get more peaceful night sleep on Ubuntu, Mint and Xubuntu Linux using gtk-redshift

Monday, March 11th, 2013

Reading Time: 2minutes

gtk redshift Xubuntu Linux screenshot sleep peacefully when using computer at late

If you want to have more peaceful night sleep when working on Ubuntu or other Debian based Linux distro, be sure to have gtk-redshift installed.
It is a little program that simply changes the color gamma of screen and makes your screen look more reddish at night. According to many scientific research done on how we humans react, whether using computer late at night. It is concluded that less bright colors and especially reddish color gamma relaxes our eye strain and thus makes it easier for us to get a sleep quickly once in bed. gtk-redshift is available in latest Ubuntu 12.04 as well as on other Ubuntu derivatives (Xubuntu, Mint Linux) etc.

Easiest way to install it is via respective GUI Package Manager or via good old Synaptic (GUI aptitude frontend).
I personally prefer to always install Synaptic on new Desktop Linux PCs, use it as package GUI frontend, for the simple reason it offers one very similar "unified" package Installer outlook across different Linux distros.

The quickest way to use GUI version of Redshift is to install with apt:

root@xubuntu:~# apt-get install --yes gtk-redshift

To further use it it needs one time to be run with color gamma paraments, launch it first time via terminal with:
user@xubuntu:~$ gtk-redshift  -l 52.5:13.4

It is a good idea to make a tiny shell script wrapper with good settings for gtk-redshift and later use this shell wrapper as launcher :

root@xubuntu:~# echo '#!/bin/sh' >> /usr/local/bin/gtk-redshift
root@xubuntu:~# echo 'gtk-redshift' >> /usr/local/bin/gtk-redshift
root@xubuntu:~# chmod +x /usr/local/bin/gtk-redshift

From then on, to launch it you can directly open it via terminal

user@xubuntu:~$ /usr/local/bin/gtk-redshift

To make the program permanently work, make it run via respective GUI environment startup . In GNOME add it start-up from:

user@xubuntu:~$ gnome-session-manager

Important note to make about gtk-redshift is that on some older monitor screens, very early in morning the screen becomes too red, making screen look like displaying on very old long time used CRT monitors. For people working in fields like; Web Design, Architecture, or any drawing twisted colors effect will be annoying and will probably interfere with your perception of colors. However for programmers, system administrators and people who use computer mainly for typing and reading gtk-redshift is huge blessing.

Enjoy ! 🙂

Improve your night sleep (Insomnia) on Linux with redshift

Friday, February 15th, 2013

Reading Time: 4minutes

sleep better at night while using Linux with redshift command line and gui applet / improve your insomnia while being a linux user
For a while I've been experiencing troubles with getting asleep. As I work in the field of IT already for 10 years and with time it seems the problem is accelerating. I've read on the internet a lot on the topic of getting asleep and how this relates to computers and computer equipment use and came to the conclusion one of the main reasons I have troubles getting asleep is I use computer late at night usually I use PC until 2, 3 o'clock. Then when I go to bed, I cannot fall asleep until its early in the morning usually 6, 7 in the morning. My main operating system on notebook is Linux so almost all of the time I use Linux. I've noticed when I occasionally use Windows, my eyes tend to be less strained afterwards and I sleep better. Thus I suspected there should be some kind of tool in Linux which changes how PC screen displays to make eyes more relaxed. I didn't have the time to research seriously and before some time the little research I've done on this led me to nothing. Just a week ago, I've read one of the articles in Linux Magazine (December) issue, there is a very thorough article in it on how to avoid headaches and eye strain using a tiny tool which changes monitor screen gamma calledredshift. In this article will explain in short how to install and use redshift to make your PC work less stressful and improve your sleeping at night. I'm using Debian as a basis Linux distro and thre redshift is available via package, other deb derivatives Ubuntu, Xubuntu etc. aslo have it. For Fedora and most of other Linux distributions redshift is also available from default repositories. For those who use Slackware or some older Linux distributions, redshift has to be installed manually from source but this should be trivial.

1. Install Redshift and Redshift-gtk packages

To install on Debian and Ubuntu:

# apt-get –yes install redshift redshift-gtk

On Fedora install with yum:

# yum -y install redshift

After installed you will have two programs to tune the screen color temperature, one is console based ( redshift ) and the other one is GUI based ( gtk-redshift ).

redshift-gtk is a GUI frontend

Here is a list of redshift tool options:

2. Changing color gamma with redshift

hipo@noah:~$ redshift -h
Usage: redshift -l LAT:LON -t DAY:NIGHT [OPTIONS...]

Set color temperature of display according to time of day.

  -h        Display this help message
  -v        Verbose output

  -g R:G:B    Additional gamma correction to apply
  -l LAT:LON    Your current location
  -m METHOD    Method to use to set color temperature (randr or vidmode)
  -o        One shot mode (do not continously adjust color temperature)
  -r        Disable initial temperature transition
  -s SCREEN    X screen to apply adjustments to
  -t DAY:NIGHT    Color temperature to set at daytime/night

Please report bugs to <>

To set your screen to Reddish mode which will relax your eye strain and therefore – when you go to sleep you have a better sleep, type:

 hipo@noah:~$ redshift -l -35:-56 -t 5000:3300

Other monitor red-color afternoon or night time gamma to relax your eyes is;

hipo@noah:~$ redshift -l 52.5:13.4

3. Setting redshift to auto change screen gamma via cronjob

If you prefer automatically changing color gamma to reddish at night – will make your eyes (and hence organism) less alert set as a cronjob in lets say 22:00 o'clock at night;

 hipo@noah:~$ crontab -u root -e

00 22 * * * redshift -l -35:-56 -t 5000:3300 2>&1 >/dev/null

4. Controlling manually between standard and reddish color gamma through gtk-redshift

For people who like to control and switch between color gamma using GNOME Applet run gtk-redshift like so:

hipo@noah:~$ gtk-redshift  -l 52.5:13.4

gtk redshift gnome applet screenshot Debian Linux

Clicking on the icon of redshift the color gamma gets changed to red, another toggle reverses back to normal.

There is another tool called F.lux which does the same as redshift. F.lux precedes redshift, actually redshift author write it as attempt to create superior F.lux. Flux works on Windows and Mac OS X – so users who work at night on this platforms might want ot check it. I tried installing f.lux on my Debian Squeeze Linux but had troubles because of requirement for newer python-appindicator :

noah:/home/hipo# apt-get install fluxgui
Reading package lists... Done
Building dependency tree      
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 fluxgui : Depends: python-appindicator (>= 0.0.19) but it is not installable
E: Broken packages


Probably with some tampering I can make f.lux work but I was lazy and since I already had redshift, I decided to quit and just be a happy redshift user.