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Computing: Eye Strain? Headaches?

If you find your eyes becoming tired towards the end of the day, or you get headaches using your computer, you may have your video refresh set too low.

CRT monitors work by refreshing the entire display many times per second. The slower the refresh, the more noticeable the flicker. A faster refresh provides less noticeable flicker and is easier on your eyes.

A slow refresh is 60Hz (60 times per second), which generally produces a terrible, noticeable flicker. A better rate is 75-80Hz, which is generally flicker-free. A spectacular rate is 90-100Hz. Most systems should be able to do at least 75Hz, but modern computers should be in the 90-120Hz range.

Some people are more sensitive to flicker than others. You may not think that your monitor flickers, while others may find it unbearable. However, even if you are unaware of the flicker, the chances are if it is less than 70-75Hz it is causing you some sort of eye strain.

You can't choose any refresh rate you want. The rate possible on your system is dependent on the capabilities of the video card and the monitor and the resolution and colour depth. Unfortunately many video drivers set themselves to the lowest setting to achieve maximum compatibility, so even if you have a modern system, you may still be using a slow refresh rate.

To modify your settings, go to Start, Settings, Control Panel, Display, Settings. Depending on your operating system and video drivers, the refresh setting may be under the Advanced screen or it may be elsewhere. Some older video drivers do not have a control for the refresh rate, so you'll need to obtain the latest drivers for your video card.

If you find the Refresh setting, change it to the next highest rate and choose Test or Apply. Windows will switch to the new mode for a few seconds so you can verify it works. Not all refresh rates can be used, however. For example, if you have a relatively new video card but an old monitor, your monitor will not be able to use a higher refresh and it will look like a snowstorm.

The refresh/flicker problem does not occur on TFT monitors and notebooks, but the video drivers may still show a refresh rate. In this case the refresh rate is set to a low number such as 60Hz to give the video card less work to do. Don’t set a high refresh if you are using a TFT display — it doesn’t have any effect and gives your video card more work to do (see also Fuzzy Display on TFT Monitors).



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