Glare in lighting installations: objective measurement of light scatter, assessment of and neural correlates of discomfort glare

An EPSRC funded research project based^[1] at:

Positions available

Applications are invited for two research studentships for 3 years (leading to a doctorate degree). The appointments can start any time from 1st July to 1st October 2009. The successful applicants will join a multidisciplinary project team to study fundamental mechanisms of glare, novel techniques for the measurement of the scatter function of the eye and the assessment of discomfort glare, ways of minimising glare in lighting installations and also fMRI studies aimed at revealing possible neural correlates of discomfort glare.

Accurate and objective measurements of the scatter function of the eye

The amount of scattered light in the eye and its angular distribution increases with age and this correlates with increased susceptibility to glare. Light scatter in the eye is difficult to measure objectively. Recently, we have developed novel equipment that measures scattered light in the eye objectively. The new technique involves direct estimates of the light scatter function using fundus imaging methods that are both rapid (~4 minutes test) and more accurate than conventional clinical and visual psychophysical tests. The new technique requires experimental optimization and refinement of existing software so as to automate the measurement procedure and the processing of results. Once fully validated, this objective test will make it possible to measure quickly and accurately the scatter function of the eye and to assess its potential uses in normal subjects and in patients with increased scatter.

Measurement of discomfort glare

A new experimental set up will be constructed in order to measure the subject's threshold for discomfort glare. Subjects will perform tests where they have to judge the luminance of a series of different size / intensity glare sources to determine the comfort/discomfort border. This approach will make it possible to establish how disability glare (measured objectively) relates to the subject's threshold for discomfort glare.

Effects of discomfort glare on distributed attention in visual tasks

Older people tend to have more problems in coping with glare sources and this makes lighting difficult since in general they also need more light to perform common visual tasks. With the population of the UK aging it is important to understand the principal factors that cause increased scatter in the eye and how these factors affect the perception of glare and visual performance. Older people also find it more difficult to process visual events that happen simultaneously at the fovea and in the periphery of the visual field. The ability to process visual information in parallel and to distribute attention to simultaneous events over the visual field has been shown to be important in driving and other occupational tasks. A new Attention and Vision (AV) test will be developed to quantify this ability and to investigate the extent to which performance in the AV test is affected by the presence of glare sources and the subject's threshold for discomfort glare. The new AV test will be used as an indicator of the subject's visual performance under both normal and "glare" conditions of illumination.

Establishing neural correlates of discomfort glare

It is of great interest to establish whether there is significant difference in brain activity between subjects with low and high thresholds for discomfort glare (with roughly equivalent levels of disability glare). A subgroup of subjects who experienced the worst effects of discomfort glare and another subgroup with greater tolerance for discomfort glare will be given various visual tasks and their brain activity recorded. We hope to establish whether the sensation of discomfort glare is associated with distinct patterns of brain activity.

Qualifications needed for these studies

These investigations bring together complementary, but diverse skills and the opportunity to train in a unique, multidisciplinary research environment. The various studies involve significant fundamental research, the development of novel tests and the need to find solutions to practical lighting applications. The work is exciting and challenging and is therefore ideally suited to graduates with a keen research interest in lighting, attention and vision science. Curiosity, enthusiasm and determination are the most important requirements, together with basic training in vision sciences, physics / optics, computing / instrumentation or experimental psychology.

How to apply?

If you wish to apply, please download and fill in the postgraduate research application form and return with your CV (which should include the names of three referees) to:

Deadline for application is Thursday 28th May 2009.

If you wish to discuss any technical aspects of the proposed investigation, please contact Prof John Barbur.

[1] In collaboration with:

Research at City University | Applied Vision Research Centre Home | Optometry Department Home