New technology also brings new problems.
Looking at a computer screen or video display unit for eight
hours or more each day can be pretty stressful. This leads to
problems with your eyes as well as with your posture.
CVS
is defined as a complex of eye and vision disorders related
to near work, which is experienced during or related to computer
usage.
CVS
is the single largest health hazard related to computer work
today. If you are the kind of person who spends most of the
time working on the computer everyday, you are likely to suffer
from CVS. An estimated 800 million people in the world already
do. Ignoring CVS can prove to be very costly, as it is known
to cause serious immediate and long-term health problems.
What
is Computer Vision Syndrome?
When working on the computer, your eyes move from the screen
to the keyboard to your presentation on the table about 25,000
times. While doing this, your eyes are exposed to different
intensities and frequencies of flicker of light. To survive
this task, your eyes are required to adjust to the flicker of
the monitor, accommodate (to remove blurred images), converge
(to remove double images) and adapt (to various luminance's)
25,000 times a day approximately.
The
strain your eyes are subjected to is equivalent of doing 50
push-ups every minute day-in and day-out. But the ordeal does
not end there. Tired and beaten, your eyes are further punished
by the harsh glare of the computer screen.
How
Soon Does CVS Develop? Because working on a computer
is a visually demanding task, often in a compromised visual
environment, various forms of discomfort and decreased performance
occurs.
| 1 hour /
day |
27% |
| 1-2 hours |
72% |
| 2-3 hours |
85% |
| 3-4 hours |
100% |
Some
of the common symptoms of CVS include:
-
Eye
strain (sore eyes or eye fatigue)
-
Headache
-
Blurred
vision
-
Slowness
in changing the focus of eyes (distance to near and back)
-
Blur
in the distance after near work
-
Glare
(light) sensitivity
-
Eye
irritation (burning, dryness, redness)
-
Contact-lens
discomfort
-
Neck
and shoulder pain
-
Back
pain
The
best way to avoid CVS is to take corrective action immediately
by designing an ergonomically correct work place. That means
proper lighting conditions that do not strain the eye, monitor
level slightly lower than the line of vision, arm and palm rests
to ease the pressure while typing, and an anti-glare screen
if possible.
A
few simple rules you can follow to ease the eye-fatigue while
working on the video display terminal:
-
After
every half hour, break eye contact with the computer display.
Look out of the window or just walk around.
-
As
the blink rate goes down while working on a computer, lubricating
drops can be used to alleviate symptoms.
-
Use
glasses that have an anti-glare coating.
-
Maintain a comfortable reading distance from the computer
display. Do not peer into it. 2 to 2.5 feet (55-75 cm) is a
safe distance
-
See
that the lighting in the room is indirect and diffused.
-
A
periodic checkup with an eye specialist to monitor any invisible
injury to the eyes.
Eye
problems
- Dry eyes
- Redness or irritation in the eyes
- Discomfort for contact lens users
- Eye fatigue
Precautions
to be taken
- For dry eyes, you can use artificial
tears to wet the eyes
- The most convenient position for our
gaze is to look a few inches below eye level. When you are
seeing at this level the shoulders, neck and eyes are at a
comfortable position. Seeing things above eye level means
craning your neck and opening your eyes wider than you normally
do. Sitting like this through the day and for months or years
together will create vision and posture problems. Lower your
computer monitor 4-8 inches below your eye level.
- Blink consciously every five minutes.
- Take a two-minute break each half
hour. Shut your eyes and roll the eyeballs behind closed lids.
Workstation
arrangement
- The monitor must be 20–30 inches
from your face. This is considered ideal distance. If the
distance is greater or less than this, it could indicate the
presence of eye problems or cause problems in vision and posture
eventually.
- The monitor must be straight in front
of you. Do not keep it at an angle.
- The centre of the screen should be
6 inches below eye level.
- The illumination should be such that
the light does not reflect from the computer screen. If bright
light from the window falls directly on to the screen, rotate
your work station to avoid it. If this is not possible, sadly,
you have to tone down the light coming in with blinds or shutters.
Similarly with florescent lights. It is good to have your
work area well lit but it becomes pointless if the bright
lights are going to bounce off the computer screen.
- Bright lights at the periphery of
vision and from directly overhead may also be irritants. Organize
the lighting so that the illumination is comfortable for you.
Corrective
equipment
- Computer glasses or spectacles with
anti-reflective coatings can be used.
- Anti-reflective screens can be fitted
on to your monitor.
