The images on my screen seem to shimmer or flicker and give me a headache – is there anything I can do?
Computers can cause headaches, but it’s usually because they’re doing or not doing something we do or don’t want. In this case it might well be that just looking at your computer screen
long enough could hurt.
As it turns out, the default settings for many video cards are often less
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The problem from the card manufacturer’s point of view is that they
cannot assume that you have anything beyond the bare minimum requirements for
a Windows compatible display. These days that typically means 640×480
resolution, 256 colors, and a 60 Hertz refresh rate.
It’s that default refresh rate that always drives me nuts.
“Refresh Rate” is, to over-simplify, the number of times each
second that the video card draws an image of your screen on the monitor.
That’s typically much faster than you or I might notice. But it’s
slow enough that as you look at your monitor, especially if you look from
side to side, you might notice a bit of flickering.
Depending on the capabilities of your monitor and video card you can
probably change your refresh rate to something else. Most video cards and
monitors support settings other than 60hz. And it doesn’t take much of a
change to make the flicker go away.
To change your monitor’s refresh rate in Windows XP:
Right-click anywhere on your desktop.
Select the Settings tab.
Click the Advanced button.
Click on the Monitor tab.
Click on the Screen refresh rate drop-down list for the
settings that you have available to you.
Select a new refresh rate if you like, and press OK.
Your system will try the new rate and give you 15 seconds to approve it. If
your screen goes completely nuts, do nothing. After 15 seconds without a
response from you the old settings will be restored.
Just about anything higher than 60hz is enough to reduce or eliminate
visible flicker. 72hz or 75hz seem popular and commonly available
What if 60hz is the only option listed? Well, there are three
You have a very old or perhaps very cheap display adapter –
this is unlikely these days.
You have the default VGA video driver installed. If you locate and install
the video drivers for your specific video card you should have access to all
the features that card has to offer, including different refresh rates.
You have an LCD screen. LCD screens typically operate at only 60hz. But
the good news is that the technology is sufficiently different that flicker
at 60hz should simply not be an issue.
Finally, the limits of your ability to view video are typically due to
your monitor. A monitor that claims to be capable of displaying, say,
1600×1200 may be able to do so but not with a crisp image. Set the
resolution as high as you can see comfortably, but no higher. Slightly fuzzy
images, like flicker, can cause eyestrain and give you a headache.