Can PCs Damage Your Health?

Posted on 3 Jul 2002 at 17:27

1 of 5

Whichever type of keyboard you use, there are some basic rules that'll make your life happier. Firstly, centre the keyboard properly: the spacebar of your keyboard should be in line with the centre of the display.
When typing, your elbows should be in line with your hips. Your forearms should be at right angles to the edge of the desk, and your hands should effectively float above the keyboard. Don't bend your wrists up or down. And make sure you can reach the upper keys without shifting your body.
You should type with a deft, light touch. Just relax. Making a clatter won't get you promoted more quickly.
Avoid resting your palms on any surface. Certainly don't rest them on your wrist rest and use your fingers to dart around the keyboard. That'd be a sure fire way of making your hands ache.
Wrists rests are great as they offer support, and so encourage relaxation. Some people don't find them necessary, though, so don't feel compelled to buy one.
If you do feel they are of benefit, make sure you get one that's the right thickness. Your rest and the lip of your keyboard should be equal in height. If the rest is too shallow, you'll wind up with poor typing posture.

Danger three:Your Monitor
A bad monitor setup can be the cause of headaches and eye strain, as well as causing neck and shoulder problems.
The positioning of your monitor on the desk is key to your comfort and health. As a rule, the display should, when you're sitting correctly, be about your arm's length away. Which, depending on your age and size, equates to between 40 and 70cm. Finally, eyes should be in line with the top of the screen.
Reflections are the enemy of all monitor users. Turn the display on its stand until the majority are eliminated, then sit head-on to the screen.
Most of all, avoid sitting with a window behind you - this causes masses of reflections. It's also inadvisable to sit facing a window. Ideally, your monitor should be at right angles to the room's main light source.
The resolution you're running at is key, too. Resolution refers to the number of dots or 'pixels' that are used to make up the image on screen. It also dictates how much you can squeeze onto your display - the greater the number of pixels, the more icons you can fit. Trouble is, the higher the resolution, the smaller all those icons will be. A resolution of 1024x768 pixels gives you perfectly legible text and icons on a 17in monitor. Any higher, and you'll be left squinting at pin-prick characters.
You should also make sure your monitor is redrawing its picture at least 85 times a second - a so-called 'refresh rate' of 85Hz. Any less, and your eye perceives the picture as flickering - and you wind up with a headache. At frequencies 85Hz and over, your eye believes the picture is stable.
Older graphics cards can struggle to refresh the picture at 85Hz, and poor-quality monitors may produce chaotic images or refuse to work at all. If your set up falls into this camp, pressure your boss into buying new equipment. Your eyes depend on it.
The focus of your monitor is also key. Look closely at characters on the screen, particularly in the extreme corners. Characters in word processed documents should be sharp, without ghosting or blurring. If a monitor's image is fuzzy, your eyes work overtime, and you're left reaching for the Optrex.
Watch out for coloured fringes in the corners of the screen, too. This is called misconvergence, and is caused by the monitor's innards being poorly aligned. This leads the red, green and blue components of the image to begin to seperate.