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IT Health & Safety Information

Use of the VDU/VDT

In most offices or buildings in Cork Institute of Technology today the VDU (visual display unit), or VDT (visual display terminal), is commonplace for both staff & students.

They are used for a wide variety of office and college work. They can also be used in engineering, architecture and various other industries for design drawings and associated artwork.

Although in this sphere the term PC (personal computer) is more commonly used. Whichever term is used, the equipment is basically the same,with the main parts being the keyboard and display screen.

If you are a user for either a part or the whole of a working day, or for periods totaling at least three hours per day,the Code of Practice for Visual Display Units will apply.

It is designed to help you avoid any possible injury or health risk while you are using the VDU.


There is concern among all involved with VDUs thats an operator's health may be at risk. Some of the common complaints are:


  • Which may include redness, dryness, soreness, temporary blurring of vision and headaches

Postural Fatigue

  • Symptoms are general aches and pains in the neck, shoulders, arms, back, thighs and lower legs.

Repetitive Strain Injury

  • Felt as persistent pain or discomfort in muscles, tendons and other soft tissues. Continuous use of a VDU requires concentrated use of the eyes.
  • Employers should develop a policy to ensure workers' eyesight problems are identified correctly and promptly.
  • Operators who normally wear bi-focal lens glasses may need a special lens prescribed if they spend a considerable amount of time at a keyboard.
  • Other problems such as fatigue and RSI can be avoided by using a well-designed work station and adopting correct posture.

Workstation Design

  • The keyboard should be separate from the screen and height adjustable.
  • The screen should be adjustable for height, horizontal swivel and vertical tilt. It should be positioned approximately at right angles to the line of sight and to avoid glare or reflections from windows and lights.
  • An adjustable copyholder should be placed between the screen and keyboard. Both the screen and the copyholder should be within 30 degrees of the viewing angle, i.e. the operator's head will be tilted downward slightly.
  • The chair must have an easily adjustable backrest for both height and tilt. The backrest should be adjusted to support the lower back.
  • The seat height must be easily adjustable and capable of being easily altered from the seated position.
  • The chair base should be five-pronged for stability, swivelled, and fitted with castors or glides for ease of movement.
  • The seat should be reasonably firm and cloth-covered to reduce any problems with static electricity.
  • There should be adequate clearance for the thighs beneath the work surface. The knees should be at 90 degrees when sitting with one hand width between the front edge of the seat and the back of the knee. The feet should be able to be placed flat on the floor; a footrest is optional.
  • The screen image should be sharply focused and free from flicker or swim. The brightness should be easily adjustable.
  • All cabling should be kept out of the way and placed in proper channels or ducting. It is dangerous to run cables across floors particularly in aisles and walkways where they create a tripping hazard, or around the work- station itself, where there is an additional risk of electrical shock due to cables being crushed when run over by the castors on the operators' chair, etc.

Working hours

  • Breaks away from the keyboard during the day can help prevent fatigue. Where an operator must spend the full shift at the keyboard it is important to take regular rest breaks of ten minutes in every hour, either by getting up and doing another task or by doing simple exercises. Click Here. They should be taken as the operator feels the need, but should not be accumulated.
  • Shorter breaks of 3 to 5 minutes taken at more frequent intervals may be more effective in reducing muscular stress.Operators should not be expected to maintain an excessive keystroke.
  • The keystroke rate per minute should be set at a rate which the individual can comfortably maintain.
  • This is particularly important for inexperienced operators and those returning after a period of absence from work who may need to work at lower keystroke rates and/or shorter work periods.


  • The information available from this site is to enligthen staff and students ONLY.
  • Cork Institute of Technology does not warrant or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information or processes disclosed.