Clinical Ocular Response Laboratory
- Professor Neville McBrien
- Dr Corrine Chan
- Mr Tim Fricke
- Ms Lauren Ayton
National & International Collaborators
- Ms Sarah Marie, Dr Bruno Decreton - Essilor, France
Ocular Response to Virtual Imagery
Virtual reality investigations in this laboratory are aimed at assessing the safety, oculomotor effects, comfort and performance of using new high-tech (often prototypic) virtual imagery devices on both children and adults. Work is often funded by national and international collaborators, allowing state of the art technology to investigate important optometric and ergonomic issues.
Much of the new human interface technology manipulates the view of the real world so that the user sees virtual imagery. This can take the form of a completely virtual environment, such as head-mounted immersive virtual reality systems, or with imagery overlaying the outside world scene, as with head-up displays. These devices may display imagery to one eye only (monocular displays), the same image to both eyes (biocular displays), or disparate images to the two eyes (binocular stereoscopic displays).
With its potential as a superior method of image presentation, virtual reality technology is finding its way into various sectors of industry including the commercial market. In occupations where workers require access to information whilst both hands are engaged in manual tasks, a monocular virtual display has the potential to increase productivity, improve quality and encourage safety. Surgeons and technicians in the automobile industry are beginning to adopt this form of hands-free access to information which allows continued focus on the external environment. In the entertainment industry, no longer are the days when movies are restricted to a television screen or hand-held monitor, binocular virtual reality devices are allowing portable viewing of DVD's and other virtual imagery. Aircraft and car head-up displays have also been utilised for many years to display virtual travel information.
However, despite these advances in this rapidly growing industry, little is still known about how the oculomotor balance of the eyes is affected by virtual imagery use. Accommodation and vergence systems are sensitive to features of the visual environment, such as proximal objects and image quality. Normally the cues to accommodation and vergence of the eyes are matched. When viewing 3D imagery, these cues may become mismatched as the accommodation demand remains fixed whilst the vergence demand is continually changing. This conflict is thought to reduce visual comfort and user performance. When viewing through monocular virtual displays, issues of ocular dominance and visual competition are also of importance. Anomalous responses of the oculomotor system and symptoms have been reported in highly demanding situations, where even minor changes could compromise safety. In addition, factors such as image resolution, cognitive demand, ergonomics and age can also affect user performance. Thus as new devices emerge onto the virtual reality scene, thorough investigations are warranted to ensure their safe introduction into the commercial market and workforce.
Accommodation & Vergence Monitoring
Evaluation of the response of the eye, not only to virtual imagery but to various external stimuli including lens treatment, are able to be performed using state of the art infra-red measurement systems, enabling dynamic accommodation and vergence monitoring in both children and adults.
Investigations into binocular vision and the treatment of non-strabismic disorders of binocular vision have also been an important component of this laboratory. The prescription of ophthalmic lenses for the treatment of vision problems is a task undertaken often on a daily basis for optometrists, however little research is available to support the effectiveness of treatments such as the prescription of plus lenses for accommodation-vergence disorders. The effectiveness of questionnaires for quantifying binocular vision disorders and the efficacy of treatment for visual information processing are also some of the other interests of this laboratory.
Selected Recent Publications
- Ames SL, Wolffsohn JS & McBrien NA. (2005). The Development of a Symptom Questionnaire for Assessing Virtual Reality Viewing Using a Head-Mounted Display. Optometry and Vision Science. 82(3): 168-176.