Almost all of us will agree that staring at a monitor harms the eyes. Those who spend the night surfing the Internet often complain of burning eyes,

Almost all of us will agree that staring at a monitor harms
the eyes. Those who spend the night surfing the Internet often complain of
burning eyes, flickering lids and blurred vision.


Studies show that the eyes shift about 30,000 times in an
eight-hour work session at the PC. The overtaxed eye cannot possibly keep up
with this kind of performance. Hazy and flickering monitors further add to the
danger. It has also been established that looking steadily at the screen for a
long time reduces the blinking frequency. This leads to the ‘Dry Eye Syndrome’.
In extreme cases, the cornea can dry up, affecting vision. In some cases, this
can also result in the loss of sight.


When you work
intensively on a computer, you may develop headaches, backache, sore or burning
eyes. In the first few months of intensively using a PC you may just ignore all
these problems. These are your body's natural ways of telling you that all is
not right in your eye’s relation with the PC. If left unattended, all these
factors may end up giving you CVS (Computer Vision Syndrome).


CVS
is caused by visual fatigue occurring due to constant shifting and focusing of
the eyes between the screen, document and keyboard, which is roughly about
25,000 times a day. The eyes have to accommodate, converge and adapt under
dissimilar ambient light on the keyboard, monitor and the document.


Go easy on your eyes[/b]


It is necessary to
understand that reading text from a computer screen is significantly different
from reading print-based materials. Unlike print-based materials which reflect
light, the computer monitor (the visual display unit, VDU) is a
self-illuminated object. Looking directly at the computer screen is somewhat
like looking into a light source. Less surrounding light may be needed or the
VDU may cause discomfort to the eyes. Poorly designed work environments may
thus accentuate the development of CVS.





Now let us take a look at some methods for
protecting our eyes. Following these measures will ensure that we are saved
from problems like CVS.


Go in for non-interlaced monitors. In many parts of the
world, such monitors are a norm. Not so in India.
Specify this detail to the hardware dealer before you buy a monitor. Most big
names have already started manufacturing non-interlaced monitors. If your
monitor is old, go over the manuals to check if it is non-interlaced. The
non-interlaced monitors have a high refresh rate and low flicker. Never buy a
monitor with a refresh rate less than 70 Hertz.


Adjust the furniture
and monitor position for a comfortable viewing distance and angle plus easy
access to the keyboard and other devices (e.g., a mouse). Most users prefer a
viewing distance of 50-66 centimeters (20-26 inches) from the eye to the
screen, or more, if large characters are displayed. Greater distance is
recommended, as this lessens the probability of visual discomfort since it
requires less convergence of the eyes and therefore, less eyestrain.
Appropriate screen location depends on eye position and line of sight. Since
the most comfortable line of sight is at least 10 degrees below horizontal, the
normal line of vision should be from the eye to the top of the screen.


Black font on a light background is easy on the
eyes. Light is broken up by the eye lens and is perceived as varying
wavelengths. The eye has to work harder to register colours than when seeing a
black and white picture. It is better that you do not work with fonts less than
7-point size.


Adjust
the brightness control or contrast knob (on some displays) to a comfortable
setting and use a task light, if needed, for working with printed material.


Glare from the screen
can usually be modified by lowering ambient light, drawing window covers
against bright light, wearing less reflective garments, choosing more
appropriate task lighting, and cleaning the display screen. Use fluorescent
tube lights or bio-lamps: these come closest to the spectral composition of
natural daylight.


Keep the display screen
clean, especially during conditions of low humidity (e.g., in the winter). This
is important as this reduces screen dust. Additionally, neutral-density or
micromesh filters may be helpful in enhancing contrast or reducing glare.


And finally, rest your eyes every few minutes. Look away from
your monitor at regular intervals.