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Screen Position
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Make sure you position the monitor
about an arm's-length away from your
screen. The precise distance depends on the size of your screen and the settings
monitors. |
| Check Monitor Set up |
All screens allow the contrast and brightness to be adjusted. For example,
working with inadequate contrast makes it harder to differentiate characters.
You tend to accept the setting provided when the machine was first set up.
As VDU screens age they can lose a little brightness, so it is worth checking
a couple of times each year that the settings suit you, the season and the
lighting environment. If you have a diagnosed eye problem, there are a range of
colour and font settings available in the operating software to improve
legibility.
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Eye Checks & Glasses
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Have your eyes checked. Most countries place an obligation on employers to
provide this and there might be financial assistance available.
As eyes age, they need some help. Experts are coy about setting age limits
but most people over 40 would benefit from a pair of glasses when working at
their computer.
Bifocal lenses are not ideal computer-wear. They force the user to move their
heads up and down to switch between the close and distant viewing when working.
Anything less than a full sized lens is going to cause problems for prolonged
use. Most opticians can produce a lens that is optimised for the way you work.
If you are over 30, it might make sense to have a pair of spectacles which you
keep beside your
computer.
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Lighting |
The lighting level is crucial to relaxed working. It is a simple matter of physics.
If the pupils are small, the eyes can scan the screen and work area without the
need constantly to adjust the focus. As the pupils dilate to admit more light,
they have to focus more precisely.
So, inadequate lighting forces your eyes to maintain accurate focus. The eyes
do this automatically but the muscles will fatigue. You might also end up
adopting an inappropriate position to accommodate your tired eyes.
The scientifically curious could look at a posh camera from the days before
auto-focus. There was a complex engraving on top of the lens that allowed the
picture-taker to see what would be in focus. With a pinhole almost everything is
in focus but open up the lens to let more light in and the depth of field is
dramatically reduced. (Squinting is one way we adopt of improving focus by
increasing the depth of field).
But more light is not automatically better. If your computer screen looks
washed out it is probably because there is too much direct light falling onto
the screen. Too much lighting can cause glare or reflection. Both may lead to
eye strain and headaches
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Relax
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Your eyes have muscles. In the relaxed position, the focus rests at infinity.
Follow the 20/20 rule - every 20 minutes, look away for at least 20 seconds. |
| Blink regularly |
Blinking is a reflex, but we tend to blink less when concentrating. If you are
tense, you also tend to stare. Blinking keeps the surface moist, dust-free and
clean. Dry eyes become increasingly uncomfortable, tempting one to rub them.
Rubbing might make the eyes water more because of the damage done! So avoid
rubbing and keep blinking.
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Eye exercises
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No one has proposed a fitness training regime for normal eyes. These
exercises will not, as far as we know, make the eye muscles bulge. But sometimes
you have to work long hours and eye exercises can relax and ‘reset’ the
muscles.
You could try this: Close your eyes, cover them with your hands. Now take
several deep breathes then open your eyes and adjust to the darkness. Uncover
your eyes gently and allow your eyes to adjust to the light and refocus. The
whole procedure can be complete in half a minute.
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The former can be provided by general room lighting. The latter is best done
with an adjustable lamp which can be positioned to avoid reflections etc. Spot
lights produce uncomfortable amounts of heat and cast shadows, so are best
avoided.
With too much ambient light, your computer screen will look 'washed-out' because of glare made worse by a dust-covered screen. This makes
reading and typing more difficult and can force you to adopt unbalanced postures
to avoid reflections.
Natural light can be good for the soul but is also responsible for
reflections and glare. Careful positioning of screens and blinds can help
relieve the adverse effects especially at low sun angles.
Multiple light sources help avoid shadows although a single fluorescent tube
can provide a good source of office light.
Does computer use damage your eyes?
The consensus is that intensive computer use will uncover, rather than cause,
eye problems. Before you assume that you have an eye problem associated with
your computer, check the environmental conditions such as lighting levels and
reflection, to make sure these are not forcing you to strain your eyes or other
muscles to compensate.
As our eyes age, focusing on small print becomes difficult. Most people over
the age of forty start to develop presbyopia. Letters look fuzzy, so you start to hold
things further away and reading in low light gets difficult. 'Night
blindness' also becomes more common as we age. We become less sensitive to
colour, particularly in the short wave, blue end of the spectrum.
So, if you are spending time at the computer, it is worth making sure that
you follow these guidelines and take good care of your eyes.
