Apple twentieth anniversary mac Servicehandbuch
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
(about 6 meters). Improper lighting can hasten the development of eye fatigue. Although eye fatigue is
annoying, there’s no evidence that it leads to permanent damage.
occurs because the eye muscles must work harder to view an object that’s closer than about 20 feet
(about 6 meters). Improper lighting can hasten the development of eye fatigue. Although eye fatigue is
annoying, there’s no evidence that it leads to permanent damage.
Whenever you’re engaged in an activity that involves close-up work—such as reading a magazine, doing
craft 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.
craft 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:
m Arrange your work space so that the furniture is properly adjusted for you and doesn’t contribute to
an awkward working posture.
m Take frequent short breaks to give your muscles and eyes a chance to rest.
Arranging your office
Here are some guidelines for adjusting the furniture in your office to accommodate your physical size
and shape.
and shape.
m An adjustable chair that provides firm, 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). Follow the manufacturer’s
instructions for adjusting the backrest to fit your body properly.
instructions for adjusting the backrest to fit your body properly.
m When you use the computer keyboard, your shoulders should be relaxed. Your upper arm and
forearm should form an approximate right angle, with your wrist and hand in roughly a straight line.
You may have to raise your chair so your forearms and hands are at the proper angle to the
keyboard. If this makes it impossible to rest your feet flat on the floor, you can use a footrest with
adjustable height and tilt to make 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 keyboard
tray that’s lower than the regular work surface.
keyboard. If this makes it impossible to rest your feet flat on the floor, you can use a footrest with
adjustable height and tilt to make 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 keyboard
tray that’s lower than the regular work surface.
Appendix A
278