Neck-shoulder discomfort at visual display unit work places. Influence of multifocal lenses on eye-head movements

Purpose. In subjects at visual display unit (VDU) work places (>4 h daily) with neck and shoulder complaints the eye-head movement and its influence through a multifocal lens design was examined. Materials and methods. The eye-head movement (head-eye mover ratio horizontal) was determined in 100 presbyopic subjects with the Vision Print (R) (Essilor). The subjects were randomized and single-blind divided into three different interventions, group I head mover, group II eye mover design, group III near work design and a control group with no intervention. Results. A work station in presbyopic subjects with neck-shoulder discomfort seems to contribute to the manifestation of a pathological stereotype (eye mover) in the horizontal gaze shift. By using multifocal spectacle lenses a significant reduction in complaints in the shoulder and neck area was found for the groups I, II and III. The change of the head-eye mover ratio (horizontal) in the direction of increased head movement was tendentially shown in the treatment groups but not for the control group. The influence of the eyhead movement in the vertical direction was not investigated. Conclusions. If optometric treatment is required (single or multifocal glasses) for a patient with neck and shoulder complaints a modification of the work place and the spectacles used is necessary before a therapeutic intervention and not vice versa. Concomitant to this a consultation for movement stimulating working conditions must take place.