Quite often we hear people say that they can’t read for long behind a computer monitor, because they get headaches, or annoyed eyes from reading on these devices.
I once got a read out of a $200 science book I was given, where they explained the science behind correct monitor calibration, and I’ve thanked the writer of that book ever since!
To make a long story short, there are 2 main different ways to calibrate your monitor’s brightness,
The first one is for watching movies or films;
During a movie or film, most part of the screen is colored or dark, unlike reading a text.
You will want to set your monitor so, that you can differentiate the darkest colors on a completely black background in a movie, so upping the brightness might be necessary.
However, whatever is comfortable for movie watching, isn’t comfortable for regular reading (black text on a white background, like websites, text or word documents, PDF’s, emails, and company programs).
The correct way to calibrate your monitor, is to completely tone down the brightness and contrast, so the screen will look very dark to your surrounding. Then focus your eyes on an object beside, or behind the monitor (look at the scenery, or wall behind the monitor), and from peripheral vision, try to dial in the monitor’s brightness until it becomes just as bright as the background.
Not darker, nor lighter.
Once you’ve set the monitor to be about even in brightness as the background (on many monitors that would mean brightness at 0%, contrast between 0 and 50%), then dial up the brightness by a notch (click) or two; just to bring it a bit more to the foreground.
(Quite often you’ll need to play with contrast, as on lower quality monitors, changing contrast from stock, could cause discoloration or lousy reflection of colors).
If the monitor is equal in brightness from the background, or lower, background images will draw attention to your brain, and you’ll be more distracted.
If the monitor is set too dark, you’ll probably feel annoyance in the eyes, or can’t read the text very clearly.
If the monitor is set too bright, your eyes and mind will tire faster.
If the monitor is calibrated just right, you should be able to read with much more comfort, suffer much less of headaches, and are saving your eyes from harm.
I have 18/20 to 19/20 vision, and been behind a monitor since an early age (now for almost 30 years).