AbstractThe present thesis investigates pattern glare susceptibility following stroke and the immediate and prolonged impact of prescribing optimal spectral filters on reading speed, accuracy and visual search performance.
A case report has shown that visual stress can occur following stroke. The use of spectral filters and precision tinted lenses proved to be a successful intervention in this case, although the parameters required modification following a further stroke episode.
Stroke subjects demonstrate elevated levels of pattern glare compared to normative data values and a control group.
Initial use of an optimal spectral filter in a stroke cohort increased reading speed by ~6% and almost halved error scores, findings not replicated in a control group. With the removal of
migraine subjects reading speed increased by ~8% with an optimal filter and error scores almost halved.
Prolonged use of an optimal spectral filter for stroke subjects, increased reading speed by >9% and error scores more than halved. When the same subjects switched to prolonged use
of a grey filter, reading speed reduced by ~4% and error scores increased marginally. When a second group of stroke subjects used a grey filter first, reading speed decreased by ~3%
but increased by ~3% with prolonged use of an optimal filter, with error scores almost halving; these findings persisted with migraine subjects excluded.
Initial use of an optimal spectral filter improved visual search response time but not error scores in a stroke cohort with migraine subjects excluded. Neither prolonged use of an
optimal nor grey filter improved response time or reduced error scores in a stroke group;
these findings persisted with the exclusion of migraine subjects.
|Date of Award||4 Feb 2013|
|Supervisor||Leon Davies (Supervisor)|
- pattern glare
- spectral filters
- visual search
- stroke patients