Effect of stimulus duration in flicker perimetry.
We investigated the relationship between stimulus duration and flicker thresholds when flickering stimuli were presented on luminance pedestals. Mean-modulated flicker thresholds remained constant with changes in stimulus duration. However, flicker presented on a luminance pedestal gave masking at short durations, decaying exponentially to stable thresholds with time. These stable thresholds were elevated when compared with the mean-modulated condition. The lowest threshold in a stimulus onset asynchrony function predicted the threshold obtained from a luminance-pedestal flicker stimulus of the same duration. This suggests that luminance-pedestal flicker thresholds are determined by the most detectable cycle in a multiple cycle stimulus. We find that the 800 ms stimulus duration used in the Medmont M600 perimeter (Medmont, Camberwell, Australia) is suitable to determine stable flicker thresholds.
Anderson
A J
AJ
Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia.
Vingrys
A J
AJ
D000328:Adult; D006801:Humans; D008027:Light; D011601:Psychophysics; D013997:Time Factors; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*