Postural modifications of VDU operators wearing bifocal spectacles

Area of Science:

• Ergonomics
• Ophthalmology
• Occupational Health

Background:

• Presbyopia, an age-related condition, affects near vision and often necessitates corrective eyewear.
• Visual display unit (VDU) workstations are common in many professions, requiring specific visual and postural adaptations.
• Previous research indicates potential links between eyewear and musculoskeletal discomfort in VDU operators.

Purpose of the Study:

• To investigate the postural effects of wearing bifocal spectacles on presbyopic VDU operators.
• To quantify changes in head, neck, and wrist movements associated with bifocal use.
• To explore the relationship between spectacle use and reported symptoms of asthenopia and musculoskeletal pain.

Main Methods:

• Observational study involving presbyopic VDU operators aged 47-58.
• Comparison of postural movements (head, wrist, elbow) while wearing bifocal spectacles versus single-vision occupational spectacles.
• Qualitative reporting of symptoms including neck/back aches and asthenopia.

Main Results:

• Operators experienced significantly greater head movements (2-3 times) when using bifocals compared to single-vision lenses.
• Increased wrist and elbow flexion movements were observed with bifocal spectacles.
• No correlation found between head movement magnitude and the reading segment position on bifocal lenses.

Conclusions:

• The use of bifocal spectacles induces static loading on neck and back muscles in presbyopic VDU operators.
• Postural changes, particularly increased head and upper limb movements, contribute to musculoskeletal discomfort and asthenopia.
• Prescription of appropriate single-vision occupational spectacles may mitigate these adverse effects.