The visual conditions for your eyes should be good, so that you can see the working object clearly. The objects should be 50 cm away from the eyes, providing that they are not too small. If the objects are very small they should be placed on a raised surface or it may even be necessary to use some form of magnifying glass. Operation of sophisticated equipment such as microscopes or computer display units while sitting puts enormous demands on the worker.
Concentrating on small objects through a microscope or watching a monitor screen for a long period of time puts a considerable strain on the eye muscles. It can even result in blurred vision, though after resting, normal vision returns. This form of static load on the muscles of the eyes causes headache and eye strain.
In addition to visual and postural conditions, the display unit operators should be given frequent breaks to avoid excessive fatigue. An uncomfortable sitting position can also lead many problems. The ocular angle of the microscope should be adjustable. The work chair should also be adjustable and have support for the back.
Discomfort arising from work with sitting operations of machines or display units can be reduced by doing :
- Careful adjustment of the display or lens conditions to suit individual vision.
- The eye-to-display distance and the display positions should be adjusted to the worker.
- Adjustment of the general lighting in the workplace to the quality of illumination.
- Required or the provision of special lighting in the work areas.
- Varying the work as much as possible, so that rest for longer periods of time from work which puts a strain on the eyes is possible.
- Ensuring that individuals have the right to take a break in a separate room in order to rest their eyes.
- Ensuring that the work chair is adjusted to a suitable height and that the sitting position is comfortable.
Another cause of uncomfortable working positions is protruding machine parts. Sometimes parts of machinery or other equipment are located so that the worker has to twist his body in order to look around the corner. Such equipment and machinery is all too common.