VDU Screening for Workplace Requirements

Practical Experience
We have many years experience in advising local industry about Vision in the Workplace. This has involved seminars both in our practice and on the client’s premises, together with many site visits and the visual screening and eye examination of thousands of employees. In addition to working with VDU operators and their work areas, we advise on eye protection from both mechanical and chemical hazards, lighting of work areas and colour perception. Just recently, both David Austen and Patti Cranton gave technical support and advice to a lecturer from Nottingham Trent University who presented a lecture on Colour Perception and Electronic Display Devices to industrial workers in display screen technology at Dundee University.

Visual Discomfort and VDUs
It is generally agreed that visual display units (VDUs) do not cause damage to the eyes, however, visual discomfort is twice as common among VDU operators as the rest of the working population. The symptoms include fatigue, prickling or grittiness of the eyes and excessive sensitivity to light. The usual causes of visual discomfort are uncorrected focussing errors of the eyes or poor coordination between them. A full and regular eye examination with an optometrist will reveal either of these problems together with any disease conditions that may be present. Exercises, spectacles or contact lenses may be all that is required to relieve the discomfort. Also, occasionally special multifocal prescription lenses designed for VDU use best alleviate visual discomfort relating to prolonged VDU use.

Many people spend most of the working day in front of a computer screen. This example is of Sarabdip Ryatt, who, like all of the optometrists at this practice, inputs his patient clinical notes into the computer. Thus good VDU working conditions are important at the practice.

Minimising other discomforts when using VDUs

Badly positioned chairs, keyboards, VDUs and documents:

• Adjusting the chair height and back to specifically fit your height.
• Adjust screen and keyboard positioning to your preference based on your user needs.
• Footrests are sometimes helpful as long as there is still sufficient knee-room.
• Document holders with rulers should be positioned to reduce eye movements between the paper and the screen for purposes of best comfort and to help eliminate copying errors.

Unsuitable or Incorrectly sited illumination:

• Ensure that the screen is positioned so that there are no annoying reflections of windows or light fittings to reduce legibility. If this proves impossible, special anti-reflection masks or visors may prove helpful.
• If the documents are poorly lit, a separate angle-poise light can be invaluable.
• Ensure the brightness and contrast of the characters on the screen are adjusted to suit you.

Poorly maintained equipment:

• Naturally the equipment should be regularly serviced to ensure that the screen is kept clean and flicker-free.

Unsuitable working environment:

• Ventilation, temperature and humidity are all related to visual comfort since the frequency of blinking is reduced with concentration. This may be a special problem to those who use contact lenses and who need a good tear flow for safe and comfortable wear.
• If you are having difficulties with contact lenses, talk to your practitioner for further advice.