All recommendations are based upon Australian Standard AS 3590 – Screen-based workstations, Part 2
Set the eye-to-screen distance at the distance that permits you to most easily focus on the screen. Usually this will be within an arm’s length.
Set the height of the monitor so that the top of the screen is below eye level and the bottom of the screen can be read without a marked inclination of the head. Usually this means that the centre of the screen will need to be near shoulder height. Your eyes should be level with the tool bar.
People who wear bifocal or multi-focal lenses will need to get a balance between where they see out of their lenses and avoid too much neck flexing. The height of the monitor can be adjusted using a monitor riser.
Place the document holder close to the monitor screen in the position that causes the least twisting or inclination of the head.
Adjust the height of the work surface and/or the height of the chair so that the work surface allows your elbows to be bent at 90º, forearms parallel with the floor, wrist straight, shoulders relaxed.
Place all controls and task materials within a comfortable reach of both hands so that there is no unnecessary twisting of any part of the body. Most people prefer the document holder to be between the keyboard and the monitor. There are many different types of document holders available.
Using a mouse
A well-designed mouse should not cause undue pressure on the wrist and forearm muscles. A large bulky mouse may keep the wrist continuously bent at an uncomfortable angle.
Pressure can be reduced by releasing the mouse at frequent intervals and by selecting a slim-line, low-profile mouse. Keep the mouse as close as possible to the keyboard, elbow bent and close to the body.
Keyboard equipment and radiation
Computer screens emit visible light that allows the characters on the screen to be seen. Weak electromagnetic fields and very low levels of other radiation that are not visible to the human eye can be detected by sensitive instruments. Similar emissions are produced by television receivers.
The levels of most radiations and electromagnetic fields emitted from computers are much less than those from natural sources, such as the sun or even the human body, and are well below levels considered to be harmful by responsible expert bodies such as the International Radiation Protection Association (IRPA).
(sourced from the University of WA website)