Apple Macintosh PowerBook 1400 Manuel d'utilisateur télécharger pdf (Page 141)

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 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.

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 Ta ke frequent short breaks to give your muscles and eyes a chance to rest.

Arranging your work area and equipment

The suggestions in this section can help you work more comfortably with

your computer.

Chair

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.

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Health, Safety, and Maintenance Tips

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Apple Macintosh PowerBook 1400 Manuel d'utilisateur Page 141