Andreas Hoffmann UBS - Union Bank of Switzerland Web Application Development Support P.O.Box CH-8098 Zurich e-mail: andreas-za.hoffmann@ubs.com.
Marino Menozzi ETH Zurich Institute of Hygiene & Applied Physiology CH-8092 Zurich menozzi@iha.bepr.ethz.ch
Nowadays, medical screening is used in various fields, such as general medicine or occupational health screening. The objective of most applied screening examination is to discriminate a small number of conspicuous subjects from usually asymptotic individuals. Such conspicuous subjects might show high risk factors for having a disease or health problems.
The idea of the presented screening approach is to reduce the resources involved. That means, that the tests should be performed without any administrator involved during the tests.
In Germany a well known screening approach G37 is established to detect subjects showing visual symptoms for people working at VDU workplaces. For examinations as required in G37 examination a Computer-Based Screening System (CBSS) is presented in this paper covering visual screening examinations such as visual acuity for far and near viewing distance, color vision, stereo vision and heterophoria. To retrieve information on how G37 are carried out in the field, a questionnaire was sent to occupational health departments in Germany to analyze whether the G37 procedures is nowadays used as defined.
Applying visual tests to visual display units (VDU) arises technical restrictions. The size and the resolutions of the VDU used leads to discrete sizes of visual stimuli and the presentation of colors using VDUs shows that not all perceivable colors can be adequately represented. Those restrictions are to overcome to assure that discrimination of the individuals is reliable using the CBSS for visual screening tests.
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