Ergonomic Hazards. Visual Display Units
3. Specific Pathologies
The specific pathologies resulting from working with VDUs present different origins and causes and so their treatment will differ despite the goals being identical: the improvement of work conditions.
Not all the problems are attributable to VDUs themselves, although many of them are common to any workstation with similar characteristics, or they are dependent on poor treatment of the hazards and on the organisations themselves.
The most common disorders suffered by operators of VDUs may be grouped into three major areas:
- a) Visual fatigue.
- b) Physical fatigue. Postural disorders.
- c) Mental or psychological fatigue.
The following scheme shows the disorders suffered by operators of VDUs.
3.1. Visual fatigue
Visual fatigue is a functional modification, reversible in nature, resulting from excessive strain of the visual apparatus. Its symptoms manifest on three levels:
- Ocular discomfort: heaviness of the eyelids, of the eyes, soreness, itchiness, need to rub one’s eyes, somnolence, burning eye sensation, swollen eyelids.
- Visual disorders: blurring of the characters that have to be perceived on the screen.
- Extra-ocular symptoms: headaches, vertigo, uneasiness and anxiety.
3.2. Physical fatigue
This is a result of static, dynamic or repetitive muscular tension. Excessive strain of this kind can produce cervical and dorsal pain, stiffness of the neck and low back pain.
3.3. Mental or psychological fatigue
This is a result of excessive intellectual or mental effort. This type of fatigue is the one with the highest incidence among people who work with VDUs. Mental fatigue symptoms may be of three types:
- Neurovegetative disorders and psychosomatic disorders (constipation, headaches, diarrhoea, palpitations).
- Psychological disorders (anxiety, irritability, depressives states).
- Sleep disorders (nightmares, insomnia, restless sleep).
If the organism is incapable of recovering the state of normality by itself or if the unfavourable conditions of the equipment, the environment or incorrect work rationale persist, the state of stress is inevitable.
