Apple Macintosh LC 550 - Manual (Page 14)

Eye fatigue
Eye fatigue can occur whenever the eyes are focused on a nearby object for a long time. This problem occurs because the eye muscles must work harder to view an object that’s closer than about 20 feet (6 meters). Improper lighting can hasten the development of eye fatigue. Although eye fatigue is annoying, there’s no evidence that it leads to per
manent damage.
Whenever you’re engaged in an activity that involves close-up work—such as reading a magazine, doing craf
t work, or using a
computer—
be sure to have sufficient glare-free lighting and give
your eyes frequent rest breaks by looking up and focusing on distant objects. Remember to have your eyes examined regularly
.
To
prevent discomfort and eye fatigue:
n
Ar
range your work space so that the fur
niture is properly
adjusted for you and doesn
’t contribute to an awkward
working posture.
n
Ta
ke
frequent short breaks to give your muscles and eyes a
chance to rest.
Arranging your office Here are some guidelines for adjusting the fur
niture in your office
to accommodate your physical size and shape.
n
An adjustable chair that provides fir
m
, comfortable support is
best. Adjust the height of the chair so your thighs are horizontal and your feet flat on the floor
.
The back of the chair should support your lower back (lumbar region). F
ollow the manufacturer
’s instr
uctions for adjusting
the backrest to fit your body properly
.
n
When you use the computer k
eyboard, your shoulders should
be relaxed. Y
our upper ar
m and forear
m should for
m an
approximate right angle, with your wrist and hand in roughly a straight line. You may have to raise your chair so your forear
ms and hands
are at the proper angle to the k
eyboard. If this mak
es it
impossible to rest your feet flat on the floor
, you can use a
footrest with adjustable height and tilt to mak
e up for any gap
between the floor and your feet. Or you may lower the desktop to eliminate the need for a footrest. Another option is to use a desk with a k
eyboard tray that’s lower than the
regular work sur
face.
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