# Darkmode Saves Power

I had a thought recently after changing the background colour of my
terminals and desktop wallpaper to black due to getting eye fatigue.
It got to the point where my left eye would weep and due to this it
got very sore. Often, late in the evenings, I could feel my eyeball
going into spasm; not a pleasant experience!

Because it made such a difference to my eyes and was noticeably less
bright I pondered how much less energy was being used due to the
black background, so I did a little test.

I connected a power meter to the 24" IPS screen and monitored the
wattage. Firstly with a white background (10.1w) and again with a
black background (8.3w); a saving of 1.8w.

Now 1.8w doesn't seem like much. However, like anything that's
switched on for long periods of time, it all adds up! For mobile
devices with limited portable power, this can also make a significant
difference to run time...