| Dangers |
Good Practices |
| - The eyes were not designed for
concentrated unwavering focus at a fixed distance - Eyes blink much less when staring at video or computer screens and thus become dry - Illumination levels can strain and stess the eyes and reduce visual acuity - Bad contrast in ambient illuination can cause glare on the screen and fatigue the eyes |
- Take mini breaks
to focus on objects at various distances in the room - Do figure 8 exercise with head letting the eyes change focus as the head moves - Palming excercise - hold palms over eyes - Ergonomics - Set up workstation so screen is level with eyes or at most 10" down (** see illustration below) - Make sure sunlight or bright lights are not directly behind you so there is no glare. Better to be at the side - Make sure the screen is not the only illumination in the room - turn on other lights or arrange for natural light - Use a no glare screen |
| Dangers |
Good Practices |
| - The arms and hands
were not designed for fixed postions for long times. - The high impact, restricted motions of keyboarding and mouse movement create great stress - Hands, arms, wrists are subject to Repetitive Stress Injuries (RSI). These injuries represent nerve damage. In the worst cases, one can lose function in the hands. - Carpal Tunnel Syndrome injuries occur when the nerves and muscles that pass through the opening called the carpal tunnel which connects the arms and the hands are subjected to continual restricted motion. |
-Ergonomics. Set up the
workstation so the elbows are roughly at 90". (** see
illustration below) -Also the hands and wrists should be level - not bent up or down. The mouse should be located near the keyboard. - Take regular mini breaks. (every 10 minutes) - Do hand and wrist excercises (see U Maryland guide) - Consider using an ergonomic keyboard - for example split so the they match the natural angle of the hands. If you use a portable computer as your major work station with long sessions, consider using an auxillary keyboard so the ergonomics can be better adjusted |
|
| Dangers |
Good Practices |
| - Body was not designed for long
term fixed positions - Bad sitting posture can cause strain in head, neck, back, and arms - Bad sitting posture can cause strain in legs - Bad sitting posture can cause fatigue |
- Take mini breaks
with exercises (for example stretches, jumping jacks) - Ergonomic setup - back, legs and knees should be roughly at 90". Adjust chair level and or keyboard level (**see illustration above) - Feet should be firmly on the ground not hanging - If working in temporary space such as university computer lab, bring pillows, boxes to elevate keyboard if adjustable furniture is not available. |
| Dangers |
Good Practices |
| There is great debate whether
long term exposure to low frequency (60hz) or high frequency (CRT
scanning) radiation is dangerous to health. Scientific studies by
neutral parties do not return consistent results. Still there are
anecdotal reports of higher instances of cancer and birth
anomalies. Most agree the dangers if there are any focus on those
who spend the entire workday at the workstation. wiki article on hazards |
CRT use high voltage electron
guns to illuminate the screen. The screens are usually
shielded. The backs and sides are not as well shielded. One
should make sure not to position near the back or side. And a
respectable distance from the front should be maintained.
Radiation falls off at the inverse square of the distance. f=1/d2
(for example, being twice as far away means the radiation
will the 1/4 the intensity.) Consider using a radiation screen over the CRT. (Flat screens are making much of this moot) |