Visual Display's & 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. This is likely to be due to fatigue through causes such as:

- Insufficient and infrequent rest periods

- Incorrect positioning of the screen and/or documents

- Unsuitable lighting

- Poorly designed work area

- An uncorrected eyesight fault such as long sight, short sight, astigmatism or
presbyopia

- The eyes not working ‘as a team’

Any of these conditions could lead to fatigue; all can be overcome through good design of the working environment and by regular eyecare.

Take frequent breaks When you work at a VDU your eyes can be focused on the screen for long periods so it is important to take a brief rest and give your eyes a break every 20 minutes or so. You should have sufficient space behind the screen for you to be able to look beyond it and relax your eyes.

Screen settings and position
You should adjust your VDU to levels of brightness and contrast that you find comfortable. Keep the screen clean and free of dust and fingermarks. If possible, position it so that windows or other light sources are to the side rather than in front or behind it – if you can see a window or light unit reflected in the screen, move the VDU until the reflections disappear, or adjust blinds or curtains. The surface of the screen should be between 33 and 100cm from your eyes and if you are working from copy documents these should be placed at roughly the same distance to avoid continual re-focusing.

Lighting
Try to eliminate as much glare as possible from the region around your screen. This is not always straightforward, but as a general rule:

- The office lighting should be set at a level which allows the documents and screen to be read easily. Additional lighting – such as an Anglepoise lamp – may sometimes be necessary to achieve this.

- Avoid an uncurtained window directly in front of or behind your working position

- Any window reflected in the screen should be fitted with blinds or curtains

- Walls and desk surfaces should be non-reflective and neutral in colour

Spectacles Only a small proportion of users will need spectacles specifically for working at a VDU and the majority of these will be what is known as presbyopic. Presbyopia affects us all as we get older. Around the age of 45 people begin to find they lose the ability to focus on objects that are close up. Spectacles with single vision, bifocal or varifocal lenses can all be used successfully for VDU work. Contact lenses are also suitable, but wearers should try to blink regularly which keeps the lenses comfortable.

When you concentrate on the screen for long periods, your normal blinking rate slows down. Presbyopic contact lens wearers may need additional reading glasses.

Reflection-free lenses
Reflection-free lenses are well worth considering for VDU users. Because they eliminate almost all reflections VDU glare is considerably reduced, providing clearer and sharper vision.

The eye examination
Make a note of the following points that will help Kefan Optics to assess the effect that VDU work may be having on your sight:

- The date of your last eye examination

- How long you have worked with VDUs

- The number of hours per day that you work at a VDU

- The distance from your eyes to the screen, keyboard and any documents you refer to while working

- The position of the screen (eg. above or below eye level, to the left or right of your sitting position)

- The size of the screen you use, its resolution and refresh rates (if known)

- Any symptoms associated with VDU work