Visual Display Unit (VDU)

Short for visual display unit, VDU is an older British term used to describe any device used with computers to display images. For example, a flat panel display and a projector are both examples of VDUs. However, VDU is most commonly used to describe the CRT monitor, a now archaic standard that has been replaced by flat panel displays.

VDU's and Your Eyes. Although there is no reliable evidence to suggest that even long-term intensive use of VDUs is damaging to the eyes, it is true that VDU users tend to complain of eye strain more than non-users.

Symptoms can range from tired eyes to blurred vision. If VDU operators do experience any of the following symptoms they could have computer vision syndrome. If they find it difficult to focus on distant objects after using a computer, have headaches, eyestrain or dry eyes they need to take extra care when using a VDU.

More people are now using computers for work causing a marked increase in the number of people complaining of eye strain. According to the Health and Safety Executive (HSE) extensive research has found no evidence that visual display units (VDU‟s) can cause disease or permanent damage to eyes. However extended or prolonged periods of VDU work can lead to tired eyes and discomfort. As the eyes now perform more demanding tasks, it may make VDU workers more aware of an eyesight problem. It may also make those with pre-existing vision defects more aware of them if these are not corrected. Computer vision syndrome is also a common eye condition amongst VDU users.

With the rising number of people using computers at work and at home there has also been an increase in the number of people complaining of eye strain. Although scientific research has not proved a link between using computers and permanent eye damage using VDUs for a long period of time can cause some minor eye problems.

Computer vision syndrome is a common eye condition amongst VDU users. Symptoms can range from tired eyes to blurred vision. If you do experience any of the following symptoms you could have computer vision syndrome. If you find it difficult to focus on distant objects after using a computer, you have headaches, eyestrain or dry eyes you need to take extra care when using a VDU to avoid getting computer vision syndrome. It is also best to visit your optician for an eye test to rule out anything more serious.

Several symptoms can indicate digital eye strain, including:

• Sore, tired, burning or itching eyes
• Watery or dry eyes
• Blurred or double vision
• Headache
• Sore neck, shoulders or back
• Increased sensitivity to light
• Difficulty concentrating
• Feeling that you cannot keep your eyes open

Common causes of eyestrain include:

• Looking at digital device screens
• Reading without pausing to rest your eyes
• Driving long distances and doing other activities involving extended focus
• Being exposed to bright light or glare
• Straining to see in very dim light
• Having an underlying eye problem, such as dry eyes or uncorrected vision (refractive error)
• Being stressed or fatigued
• Being exposed to dry moving air from a fan, heating or air-conditioning system

There a number of things you can do to look after your eyesight when using VDUs. Follow the following advice to ensure good eye health:

Computer use strains eyes more than reading print material because people tend to:

• Blink less while using computers (blinking is key to moistening the eyes)
• View digital screens at less than ideal distances or angles
• Use devices that have glare or reflection
• Use devices with poor contrast between the text and the background

Some other factors that can make the condition worse include:

• Glare on your screen
• Poor posture
• Setup of your computer workstation
• Circulating air, such as from air conditioning or a nearby fan

Tips for preventing eye strain

• Using eye drops. A person blinks less than usual when using digital screens, and this can dry out the eyes. Drops or artificial tears can be purchased at most pharmacies, as well as online. Specialty eye drops are available for people who wear contact lenses. Preservative-free eye drops are best.
• Change computer settings. Making text twice as large as usual can reduce eye strain. Reading black text against a white background is easiest on the eyes.
• Reduce screen glare. Protective anti-glare screens can be applied to computers and eyeglasses, to prevent eye problems. Also, flat screens tend to have less glare than curved ones.
• Adjust the screen's contrast. Change settings so that the screen is bright enough to read the text without straining. The right contrast may change, depending on the presence of sunlight.
• Get regular eye checkups. Poor eyesight is a major cause of strain. Regularly attending checkups will ensure that a person has an updated prescription when needed.

Visual

A. Adjust screen angle to suit sitting height. Slightly downward viewing angle i.e. 20-40o from horizontal
B. Adjust display height to minimise head/neck movement.
C. Adjust screen to avoid/minimise reflections and glare.
D. Adjust screen brightness and contrast
E. Vary viewing distance over working day.

Additionally:

• Where document holders used, place at same height, plane and viewing distance as screen to minimise head/neck/eye movement.

• Adjust blinds to minimise glare.

Posture eResearch by Navid Ajamin –- Spring 2008

1. Adjust backrest to support lower back
- Do not slouch
- Sit right back in chair to gain proper support
2. Adjust seat height so have room between legs and table.
3. Knees level with hips
4. Elbows close to sides
3. Adjust height so forearms horizontal
4. Wrist slightly flexed
5. Keep a clear area in front of keyboard to rest wrists when not typing consider using a wrist rest
6. Use foot rest, if required
7. Keep mouse and keyboard within easy reach, avoid over stretching to use mouse

Organisational

• Keep area under desk clear. Remove obstacles.

• Move PC tower unit if this is restricting leg movement.

• Keep desk as clear as possible,but …
  … with supplies close at hand.

• Keep space into/out of workstation clear and free of obstructions.

• Take short breaks every now and again.

• Break-up VDU work with non VDU work

• “Stretch your legs”.

• Rest arms and shoulders periodically.

• Avoid high activity wrist movements during work breaks.

Reference:

unison.org.uk eyehelp.co.uk mayoclinic.org medicalnewstoday.com eyecaretrust.org.uk